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JOMO KENYATTA UNIVERSITY OF AGRICULTURE & TECHNOLOGY
SCHOOL OF OPEN, DISTANCE AND eLEARNING IN COLLABORATION WITH FACULTY OF SCIENCE
DEPARTMENT OF ZOOLOGY P.O. Box 62000, 00200 Nairobi, Kenya
SZL 2111 HIV/AIDs
LAST REVISION ON April 17, 2013 K. O. OGILA ([email protected])
JOMO KENYATTA UNIVERSITY OF AGRICULTURE & TECHNOLOGY SCHOOL OF OPEN, DISTANCE AND eLEARNING P.O. Box 62000, 00200 Nairobi, Kenya E-mail: [email protected]
SZL 2111: HIV/AIDs
LAST REVISION ON April 17, 2013
SZL2111 HIV/AIDs
This presentation is intended to covered within one week. The notes, examples and exercises should be supplemented with a good textbook. Most of the exercises have solutions/answers appearing elsewhere and accessible by clicking the green Exercise tag. To move back to the same page click the same tag appearing at the end of the solution/answer.
Errors and omissions in these notes are entirely the responsibility of the author who should only be contacted through the
Department
of Curricula & Delivery (SODeL) and suggested corrections may be e-mailed to [email protected].
iii
SZL2111 HIV/AIDs
SZL 2111: HIV/AIDs Course description General introduction: Public health and hygiene, human reproductive system, sex and sexuality.
History of sexually transmitted diseases (STDs); History
of Human Immunode ciency virus/ Acquired Immune de ciency Syndrome (HIV/AIDS), Comparative information on trends, global and local distribution, Justi cation of importance of course. Biology of HIV/AIDS; Overview of immune system, natural immunity to HIV/AIDS. The AIDS virus and its life cycle, disease progression, transmission and diagnosis.
Discordant cou-
ples. Treatment and Management; nutrition, prevention and control; Abstain, Be faithful, Condom use, Destigmatize HIV/AIDS (ABCD) methods and antiretroviral drugs and vaccines. Pregnancy and AIDS. Management of HIV/ AIDS patients. Social and cultural practices: Religion and AIDS. Social stigma on HIV/AIDS. Behavioral change. Voluntary Counseling and Testing Services. Gender and HIV/AIDS. Drug and alcohol abuse and HIV/AIDS. Poverty and AIDS. Families and AIDS orphans. Government policies: Global policies of AIDS. Legal rights of AIDS patients. AIDS Impact: Family /society setup, population, agriculture, education, health, industry, development, economy and other sectors.
Prerequisite:
none
Course aims 1. To bring about behavioral change 2. To prevent HIV/AIDS and reduce the threat it poses to youth/students 3. To promote HIV/AIDS education as a means of producing better and more integrated sense of health education in the student
Learning outcomes Upon completion of this course you should be able to know; 1. Biology of HIV
iv
SZL2111 HIV/AIDs
2. Transmission of HIV 3. Disease progression and symptoms 4. Treatment of HIV/AIDs Various strategies of managing of HIV/AIDs 5. How to prevent and control of HIV/AIDs 6. Social and cultural practices that contribute to spread of HIV/AIDs 7. Policies and rights of people living with HIV/AIDs 8. Implications of HIV/AIDs on various sectors
Instruction methodology
Lectures: oral presentation generally incorporating additional activities e.g writing on chalk board, exercises, class questions and discussions or student presentation.
Tutorials to give the students more attention.
Assignments and Demonstrations.
Assessment information The module will be assessed as follows;
10% of marks from two (2) assignments to be submitted online
20% of marks from two written CAT to be administered at JKUAT main campus or one of the approved centres
70% of marks from written Examination to be administered at JKUAT main campus or one of the approved centres
v
Contents 1 General introduction
2
1.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
1.2
Justi cation of the course
3
1.2.1
. . . . . . . . . . . . . . . . . . . .
Reasons for HIV/AIDS education/ why train in HIV/AIDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
1.3
De nition of Terminologies . . . . . . . . . . . . . . . . . . . .
5
1.4
Public Health and Hygiene . . . . . . . . . . . . . . . . . . . .
7
1.4.1
. . . . . . . . . .
7
Vaccination . . . . . . . . . . . . . . . . . . .
7
Rural and Urban Health Clinics
8
Disease Tracking and Epidemiology
Sanitation and Pollution Control
Medical Research
Public Education Campaigns
Public health programs may include:
. . . . . . . . . . . .
8
. . . . . . .
8
. . . . . . . . . . . . . . .
8
. . . . . . . . .
9
. . . . . . . . . . . . . . . . . . . . . . . . . . .
9
1.5
Types of HIV
1.6
Origin, Theories and History of HIV/AIDS
. . . . . . . . . .
11
. . . . . . . . . . . . . . . . . . . .
12
1.6.1
Mysterious origins
1.6.2
Religious Theories (God's wrath and witch craft)
. . .
12
1.6.3
Monkey origin theories . . . . . . . . . . . . . . . . . .
13
Hunter theory
13
Oral Polio Vaccine (OPV) theory
. . . . . .
13
The contaminated needle vaccine
. . . . . . .
14
The colonialism theory
. . . . . . . . . . . .
15
. . . . . . . . . . . . . . . . .
1.6.4
The conspiracy theory
. . . . . . . . . . . . . . . . . .
15
1.6.5
The calculated theory
. . . . . . . . . . . . . . . . . .
15
2 Sex education and Human sexuality vi
19
SZL2111 HIV/AIDs
2.1
2.2
What is sex education? . . . . . . . . . . . . . . . . . . . . . .
20
2.1.1
Aims of sex education
20
2.1.2
Myths surrounding sexuality
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
Sexually Transmitted Diseases . . . . . . . . . . . . . . . . . .
20
2.2.1
How do you know that you have an STD?
. . . . . . .
21
2.2.2
How STDs are transmitted . . . . . . . . . . . . . . . .
21
Factors that enhance chances of getting infected with STD . . . . . . . . . . . . . . . . . . . .
2.2.3
Prevention and Control of STIs
. . . . . . . . . . . . .
23
Importance of early diagnosis and treatment .
23
2.2.4
Basic information on some common STDs
2.2.5
Relationship between HIV and Sexually transmitted infections
. . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
3 The Immune system 3.1
22
23
28
32
Overview of the Immune System
. . . . . . . . . . . . . . . .
33
3.1.1
The bone marrow
. . . . . . . . . . . . . . . . . . . .
33
3.1.2
Types of Immunity . . . . . . . . . . . . . . . . . . . .
33
Innate/ Inborn/Natural/Non-speci c immunity; . . . . . . . . . . . . . . . . . . . . . . . . .
33
Acquired/ Adaptive / Speci c Immunity
. .
34
Cells of the Immune System . . . . . . . . . .
35
Stages in an immune response . . . . . . . . . . . . . .
38
Recognition stage . . . . . . . . . . . . . . . .
38
Proliferation stage
. . . . . . . . . . . . . . .
39
Response stage
. . . . . . . . . . . . . . . . .
40
Eector stage . . . . . . . . . . . . . . . . . .
40
3.1.4
Role of antibodies in Humoral Immune Responses . . .
41
3.1.5
Types of Immunoglobulins . . . . . . . . . . . . . . . .
42
3.1.6
Cellular (or cell mediated) immune response . . . . . .
42
Role of T lymphocytes . . . . . . . . . . . . .
43
Roles of null lymphocytes and natural killer
3.1.3
cells in cellular immune responses . . . . . . . 3.1.7
Complement System
. . . . . . . . . . . . . . . . . . .
44 45
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SZL2111 HIV/AIDs
3.2
Immunode ciency
. . . . . . . . . . . . . . . . . . . . . . . .
3.2.1
Autoimmune disorders
3.2.2
Neoplastic disease
3.2.3
Chronic illness and surgery
3.2.4
Special problems
3.2.5
45
. . . . . . . . . . . . . . . . . .
47
. . . . . . . . . . . . . . . . . . . .
48
. . . . . . . . . . . . . . .
48
. . . . . . . . . . . . . . . . . . . . .
49
Role of immune system in HIV pathogenesis . . . . . .
49
4 Biology of HIV
53
4.1
Nature of HIV . . . . . . . . . . . . . . . . . . . . . . . . . . .
54
4.2
The Structure of HIV . . . . . . . . . . . . . . . . . . . . . . .
54
4.3
The Life Cycle of HIV/ HIV Replication
56
. . . . . . . . . . . .
5 Disease progression and symptoms 5.1
5.2
Introduction
60
. . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.1
Exposure vs. Infection
5.1.2
Infection vs. Disease
Stages of HIV Infection
. . . . . . . . . . . . . . . . . .
61
. . . . . . . . . . . . . . . . . . .
61
. . . . . . . . . . . . . . . . . . . . .
62
5.2.1
Primary HIV infection
. . . . . . . . . . . . . . . . . .
62
5.2.2
Clinical asymptomatic HIV infection/ Latent phase . .
62
63
5.2.3
Initial Infection Symptoms include:
. . . . .
Symptomatic HIV infection/AIDS Related Complex (ARC) phase
. . . . . . . . . . . . . . . . . . . . . . . . . . .
63
5.2.4
Progression of HIV to AIDS . . . . . . . . . . . . . . .
64
5.2.5
Other Complications in HIV Patients
65
5.2.6
Factors that lead to faster development of HIV infection
. . . . . . . . .
to full- blown AIDs . . . . . . . . . . . . . . . . . . . . 5.3
Opportunistic Infections
. . . . . . . . . . . . . . . . . . . . .
6 Transmission and diagnosis of HIV 6.1
6.2
61
Transmission of HIV
66 67
72
. . . . . . . . . . . . . . . . . . . . . . .
6.1.1
Modes of HIV Transmission
6.1.2
Factors that increase chances of MTCT/ Determinants
75
6.1.3
Prevention of MTCT (PMTCT)
. . . . . . . . . . . .
76
. . . . . . . . . . . . . . . . . . .
77
Diagnosis of HIV and AIDs 6.2.1
. . . . . . . . . . . . . . .
73
The Enzyme-Linked Immunosorbent Assay (ELISA)
.
73
77
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SZL2111 HIV/AIDs
6.3
6.2.2
The Western blot assay
. . . . . . . . . . . . . . . . .
77
6.2.3
PCR
. . . . . . . . . . . . . . . . . . . . . . . . . . .
77
6.2.4
CD4+Cell count
6.2.5
Measuring viral load
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STIs, STDs, FGM and HIV/AIDS
. . . . . . . . . . . . . . .
6.3.1
Common examples of STIs/ STDs
. . . . . . . . . . .
6.3.2
Relationship between HIV & STDs/STIs
6.3.3
Dangers/ risks of STDs/STIs
6.3.4
Why teenagers don't seek treatment
6.3.5
FGM (Female Genital Mutilation)
80
. . . . . . . . . .
80
. . . . . . . . . . .
81
. . . . . . . . . . . . . . . . .
81
Eects of FGM leads to conditions that favours . . . . . . . . . . . . . . . . . .
Prevention and control of mother to child transmission
7.2
Prevention and control of transmission through blood and other
. . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
85
85
. . . . . . . . . . . . . . . . .
86
Ways in which HIV cannot be transmitted . . . . . . .
86
Treatment of HIV . . . . . . . . . . . . . . . . . . . . . . . . .
86
7.4.1
Nucleoside analogues reverse transcriptase inhibitors
87
7.4.2
Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
87
7.4.3
Protease inhibitors
. . . . . . . . . . . . . . . . . . . .
87
7.4.4
Entry inhibitors . . . . . . . . . . . . . . . . . . . . . .
87
7.4.5
Limitations of antiretroviral therapies
. . . . . . . . .
88
7.3.1 7.4
81
84
7.1
HIV Post exposure prevention
79
. . . . . . . . . . . . . .
7 Prevention and treatment of Hiv/Aids
7.3
79
79
Types of FGM
blood products
78
. . . . . . .
HIV survival
77
Drug resistance
. . . . . . . . . . . . . . . .
88
Drug side eects
. . . . . . . . . . . . . . . .
89
Cost of treatment . . . . . . . . . . . . . . . .
89
7.4.6
Development of new HIV drugs and vaccine
7.4.7
Challenges in Developing AIDS Vaccines
7.4.8
7.4.9
.
. . . . . .
89
. . . . . . . .
90
Treatment of opportunistic infections . . . . . . . . . .
91
Support mechanisms . . . . . . . . . . . . . .
91
Steps involved in HIV testing in VCT . . . . . . . . . .
93
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SZL2111 HIV/AIDs
Pretest counseling
Advantages of testing
. . . . . . . . . . . . .
93
Disadvantages . . . . . . . . . . . . . . . . . .
94
Post test counseling
. . . . . . . . . . . . . .
94
Role of VCT centers
. . . . . . . . . . . . . .
95
General reactions to testing HIV positive
. . . . . . . . . . . . . . .
. .
8 Concept of positive living
93
95
100
8.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . .
101
8.2
Home Based Care . . . . . . . . . . . . . . . . . . . . . . . . .
103
8.2.1
Rationale for Home Based care
104
8.2.2
Advantages of organized home based care
8.2.3
Components of home based care
8.2.4
Aspects of nutrition in comprehensive care of HIV/AIDS
8.3
. . . . . . . . . . . . .
104
. . . . . . . . . . . .
105
patients
. . . . . . . . . . . . . . . . . . . . . . . . . .
105
Advantages of good nutrition to PLWA . . . .
106
Principles of nutrition support for PLWA . . .
107
Management of pregnancy in HIV/AIDS 8.3.1
. . . . . . .
. . . . . . . . . . . .
108
Reducing the risk of transmission during pregnancy . .
108
Conception
109
The pregnancy
. . . . . . . . . . . . . . . . .
109
Delivery . . . . . . . . . . . . . . . . . . . . .
110
Breastfeeding . . . . . . . . . . . . . . . . . .
110
Testing babies for HIV . . . . . . . . . . . . .
110
. . . . . . . . . . . . . . . . . . .
9 Behavioral patterns and the spread of Hiv /Aids 9.1
Individual Behavioral Patterns and the spread of HIV /AIDS 9.1.1
9.1.2
. . . . . . . . . . . . . . . . . . . . . . .
115
Role of Gender in HIV/AIDS Transmission . . . . . . . . . . .
116
9.2.2
Safe sex and safer behaviors
115
. . . . . . . . . . . . . . .
9.2.1
9.3
114
Behaviour change could play a greater role in reducing HIV infection
9.2
113
Cultural, social, biological and economic pressures make women more vulnerable HIV that men. . . . . . . . . .
116
Remedy to above problem
117
. . . . . . . . . . . . . . . .
Drug/Alcohol Use and Abuse and the Spread of HIV/AIDS
.
118
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SZL2111 HIV/AIDs
9.3.1
Relationship between drug use and HIV
. . . . . . . .
120
10 Implications of Hiv/Aids And International Responses to the Hiv/Aids Pandemic 123 10.1 To the individual 10.2 To the family
. . . . . . . . . . . . . . . . . . . . . . . . .
124
. . . . . . . . . . . . . . . . . . . . . . . . . . .
125
10.3 To the community
. . . . . . . . . . . . . . . . . . . . . . . .
125
10.3.1 How to solve negative eects . . . . . . . . . . . . . . .
126
10.4 Multi - Sectoral Impacts of HIV/AIDS
. . . . . . . . . . . . .
126
10.4.1 Impact on Industry and business sector . . . . . . . . .
126
10.4.2 Impact on agriculture . . . . . . . . . . . . . . . . . . .
126
10.4.3 Impact on education
127
. . . . . . . . . . . . . . . . . . .
10.4.4 Impact on health sector
. . . . . . . . . . . . . . . . .
10.4.5 Impact on economic growth
. . . . . . . . . . . . . . .
10.5 Responses of African Governments to HIV - AIDS epidemic
.
128 128 129
10.5.1 Formation of institution to coordinate and ght HIV pandemic
. . . . . . . . . . . . . . . . . . . . . . . . .
10.5.2 Declaring HIV a national disaster
. . . . . . . . . . .
129 129
10.5.3 Some of the strategies adopted by the Kenyan government to ght the spread of HIV/AIDS
. . . . . . . . .
129
Solutions to Exercises . . . . . . . . . . . . . . . . . . . . . . .
136
1
SZL2111 HIV/AIDs
LESSON 1 General introduction Learning outcomes Upon completing this topic, a student should be able to:
De ne of terms related to HIV/AIDS
Understand the meaning of public health and its role in disease infection
Understand origins, theories and history of HIV/AIDS
Know various types of HIV
Global distribution and trends of HIV/AIDS
2
SZL2111 HIV/AIDs
1.1. Introduction HIV/AIDS is the worst pandemic the world has experienced in the last half of the 20th century. It has decimated whole population of people in certain region.
If one becomes infected with HIV, the virus begins to attach the
immune system. A person infected with HIV can look and feel perfectly well for many years and may not even know they are infected. Over a period of time, it is highly likely that HIV will damage the immune system and when this happens, one become vulnerable to illness often referred to as opportunistic infections that a healthy immune system would usually be able to ght o, and this leads to a condition known as AIDS - Acquired Immunode ciency Syndrome. AIDS is a collection of infections (usually severe) and cancers that may develop in people who are HIV positive. A person is said to have AIDS when they have developed one of these speci c illness, this is usually after a signi cant period of time often many years. Some people will receive an AIDS diagnosis when their T-cell count drops below 200 copies per cubic ml of blood. The eects that HIV infection may have on an individual vary dramatically. At one end of the spectrum a person may remain very well with virtually no ill eects. At the other end of the spectrum a person may have an AIDS diagnosis and develop a life threatening opportunistic infection. Currently there is no cure or vaccine for HIV/AIDS. Once a person contracts HIV, they will remain infected with the virus for life and are able to transmit the virus to others.
1.2. Justi cation of the course Education is an important component of preventing the spread of HIV. Aims of HIV/AIDS training,
To prevent new infections from taking place. i.e.
By giving people information about HIV - what HIV and AIDS are, how they are transmitted, and how people can protect themselves from infection.
Teaching people how to put this information to use and act on it practically for e.g. how to get and use condoms, how to suggest and practice safer sex, how to prevent infection in a medical environment or when injecting drugs.
3
SZL2111 HIV/AIDs
To improve quality of life for HIV positive people i.e. by -
Enabling and empowering them to improve their quality of life.
To be able to access medical services and drug provision
To be able to nd appropriate emotional and practical support and help
Teaching them about the importance of not passing on the virus
To reduce stigma and discrimination. - Discrimination against positive people can help the AIDS epidemic to spread
To help people focus upon the person than the disease and be more caring to the person.
To provide knowledge on modes of transmission especially to those affected and how to cope with the infected.
To initiate and sustain behavior changes necessary to reduce the rate of developing infections through safer sex practices.
1.2.1. Reasons for HIV/AIDS education/ why train in HIV/AIDS
HIV infection is lifelong and there is no cure
HIV is infectious, and those infected will remain infectious throughout their lives.
Fear arises from uncertainty of unpredictable medical conditions and reactions of people especially of those close to them.
Information and knowledge is incomplete about HIV care and prevention and at times even con icting.
The infected and aected are likely to have abroad of physical, psychological and social needs which may need adjustments e.g. nances.
Good management can contain some of these problems, early identi cation and intervention.
4
SZL2111 HIV/AIDs
It provides knowledge needed to initiate and sustain change in risky behavior.
It helps the infected nd a new or perhaps dierent approach to using safer sex and responsible social relationships.
It helps those who are infected to leave with the infection.
1.3. De nition of Terminologies Any specialized eld of study has some terms (jargons) that only professional in that eld comprehend clearly their meaning with reference to the subject. HIV/AIDS education is a subject that has borrowed heavily from medical sciences and therefore learners need to familiarize themselves with some terms that are commonly used in the subject 1. Rate - This is the amount of something in relation to something else shown as a proportion or percentage. Often it re ects the idea of speci c time. For example, imagine that 10,000 cases of AIDS have been reported to the ministry of health over the past ten years. You could tell someone this information alone, or you could say that the country only has a population of 100,000 people, and the rate of AIDS is 0.1, or 10% (10,000 cases divided by 100,000 people). 2. Incidence-This is how often new cases of a disease appear in a population during a set period of time, usually one year. For example, if you wanted to know the incidence of HIV in a village, you could test all the people in the village and record that information as your baseline. Then test all of the same people one year later. Count the number of people who did not have HIV during the rst test but did have the virus during the second test. Divide this number by the total number of uninfected people in the village. The result is the incidence of HIV in this village (the number of new infections per person per year). 3. Prevalence - This is the proportion of people who have a disease in a community at any one point in time. In the example above, the prevalence of HIV would be 10% the rst year (100 cases among 1,000 people
5
SZL2111 HIV/AIDs
living in the village) and 15% the second year (150 cases among 1,000 people living in the village). 4. Bias-This occurs when an unexpected factor aects the results of a study. For example, imagine you want to nd out how many pregnant women in your town have HIV. You test all the pregnant women who come to your medical clinic over a three-month period. Since people with HIV are more likely to be sick and come to the clinic, and you tested all pregnant women who came to the clinic, you will nd more women with HIV than if you tested every pregnant woman in the town. Testing only sick pregnant women in uenced your results. Your study was aected by bias. Bias can happen even when you are trying to avoid it. If you ask questions with a tone that tells people that you want them to answer in a certain way, you can bias your results.
For example, if you want
to know how many people inject drugs but ask, "You do not use those illegal, deadly drugs do you?" then fewer people will answer yes than really do use drugs. Your results will be biased. 5. Endemic- This term describes characteristic of a particular place or among a particular group or area of interest or activity. From disease point of view, the term is used to describe a disease occurring within a speci c area, region, or locale e.g. Malaria is endemic in a lot of Africa countries.
The term can also be used to describe a species of organ-
ism that is con ned to a particular geographical region, for example, an island or river basin. 6. Epidemic This is an outbreak of a disease that spreads more quickly and more extensively among a group of people than would normally be expected. Among the diseases that have occurred in epidemic proportions throughout history are bubonic plague, in uenza, smallpox, typhoid fever, tuberculosis, cholera, bacterial meningitis, and diphtheria. Occasionally, childhood diseases such as mumps and German measles become epidemics. 7. Epidemiology-This is the study of the incidence and distribution of diseases in large populations, and the conditions in uencing the spread
6
SZL2111 HIV/AIDs
and severity of disease.
For example in the study of the acquired im-
munode ciency syndrome (AIDS) epidemic in the early 1980s, both the National Cancer Institute (U.S.) and the Pasteur Institute (France) reported discovering that a retrovirus which came to be known as the human immunode ciency virus (HIV) was the main cause of the disease. 8. Pandemic a widespread epidemic that aects people in many dierent countries, across several continents e.g. HIV/AIDS
1.4. Public Health and Hygiene Public Health is the protection and improvement of the health of entire populations through community wide action, primarily by governmental agencies. Most people think of public health workers as physicians and nurses, but a wide variety of other professionals work in public health, including veterinarians, sanitary engineers, microbiologists, laboratory technicians, statisticians, economists, administrators, attorneys, industrial safety and hygiene specialists, psychologists, sociologists, and educators. Public health workers engage in activities outside the scope of ordinary medical practice and these include inspecting and licensing restaurants; conducting rodent and insect control programs; and checking the safety of housing, water, and food supplies etc. Hygiene is the science dealing with the preservation of health or the practice or principles of cleanliness. In the public domain, Public health o cers mainly manage this practice.
1.4.1. Public health programs may include:
• Vaccination This is the process of making the body resistant to a speci c disease by using a vaccine (a chemical that stimulates the body to create antibodies to ght a speci c infectious organism). Vaccination programs protect people against disease such as measles, mumps, diphtheria, and other childhood infectious diseases.
When small outbreaks of infectious disease threaten to grow into
epidemics, public health o cials may initiate new vaccination programs.
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• Rural and Urban Health Clinics Public health agencies operate local clinics that provide free or reduced-cost medical services to individuals, especially infants and children, pregnant and nursing women, people with drug abuse problems, physical disabilities, and other conditions. Public health clinics routinely screen patients for a number of infectious diseases and may provide free treatment if patients test positive. Each clinic tracks the incidence of certain communicable diseases in its area, and reports this information to national and international public health o ces.
• Disease Tracking and Epidemiology Threats to public health concerns change over time and epidemiologists and other o cials continuously evaluate epidemiological trends to determine how best to meet future public health needs.
Epidemiologists and other public
health o cials attempt to break the chain of disease transmission by notifying people who may be at risk for contracting an infectious disease. Public health o cials may also ensure that infected people complete treatment programs, so that the diseases are completely eliminated and the patients are no longer carriers of the infection.
• Sanitation and Pollution Control Disease-causing organisms are often transmitted through contaminated drinking water.
The single most eective way to limit water-borne diseases is to
ensure that drinking water is clean and not contaminated by sewage. Public health o cials establish sewage disposal and solid waste disposal systems, and regularly test water supplies to ensure they are safe. Public health programs establish and enforce laws for safe food storage and preparation;food-safety guidelines established by public health o cials.
• Medical Research Another component of public health is scienti c and medical research. Cadres of doctors and scientists work in laboratories to establish new ways to prevent, diagnose, treat, and cure disease and disability.
Scientists and doctors em-
ployed by the government conduct some biomedical research in public health facilities to nd better ways to protect human health.
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• Public Education Campaigns Many diseases are preventable through healthy living, and a primary public health goal is to educate the general public about how to prevent non-infectious diseases. Health promotion also encourages people to take advantage of early diagnostic tests that can make the outcome of disease more favourable e.g. early detection of breast cancer, for instance, increasing the chances of a cure. Detection and proper treatment of high blood pressure reduces the risk of a stroke, the leading cause of permanent disability in older people.
1.5. Types of HIV There are 2 main types of HIV:- HIV-1 &HIV-2. Both types are transmitted by sexual contact, through blood & from mother-to-child. They both appear to cause clinically indistinguishable AIDS. HIV-2 is less easily transmitted & the period between initial infection & illness is longer.
Its uncommon and
concentrated in West Africa countries, for example, Senegal, Ghana, Mali, Burkina Faso, Ivory Coast. Most HIV-2 reported in Brazil, Angola, Mozambique and Portugal can be traced back to West African contact. HIV-1 is the predominant virus world wide & generally when people refer to HIV without specifying the type they refer to HIV-1.
Example
.
HIV-1 subtypes
Group M (major) Group N (new) Group O (outlier) The 3 groups may represent separate introduction of Simian Immunode ciency Virus (SIV) into humans
Group O appears to be restricted to West-central Africa
Group N was discovered in 1998 in Cameroon & is extremely rare.
More than 90% of HIV-1 infections belong to group M
There are at least 9 subtypes within group M. They include A, B, C, D, F, G, H, J, and K.
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HIV1A found across west east axis from Ivory Coast to Djibouti via Kenya
HIV1B found in Thailand, Europe and S.America
HIV1C found in East Africa, Botswana and South Africa and is the commonest subtype globally accounting for 50%
HIV1D found in Congo, Kenya, Rwanda, Burundi, Tanzania and Uganda
HIV1E found in Thailand, Cameroon, Central African Republic and Congo
HIV1F found in Cameroon and Congo
HIV1G found in Congo and Gabon
HIV1H, J, K are rear but found in African continent.
In Kenya we have subtypes A, C, and D and this makes our country to be ranked amongst the leading countries with the highest HIV infections.
CRFs-circulating recombinant forms
- Occasionally two viruses of dier-
ent subtypes can meet in the cell of an infected person and mix together its genetic material to create a new hybrid virus in a process similar to sexual reproduction and sometime called viral sex. Many of these strains don't survive for long but those that infect more than one person are known as CRFs. E.g. CRF A/B is a mixture of subtype A&B.
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1.6. Origin, Theories and History of HIV/AIDS The origin of AIDS and HIV has puzzled scientists ever since the illness rst came to light in the early 1980s. For over twenty years it has been the subject of debate and the cause of countless arguments, with everything from a promiscuous ight attendant to a suspect vaccine program being blamed. The rst recognized cases of AIDS occurred in the USA in the early 1980s In 1981. The virus was discovered among homosexuals in the USA. A number of gay men in New York and San Francisco suddenly began to develop rare opportunistic infections and cancers that seemed stubbornly resistant to any treatment. They presented with a syndrome which included mouth rash, skin problems e.t.c. At this time, AIDS did not yet have a name, but it quickly became obvious that all the men were suering from a common syndrome. Their bodies' immunity was weakened and completely suppressed. Medics wrote their investigations in a journal. In 1983, it was discovered that the symptoms that were earlier observed were caused by a certain virus called immunode ciency virus and it was suppressing the immune system. In 1986, it became clear that the virus discovered in 1981 was spreading fast and many people suered from the same condition. In 1986, in West Africa, another virus was discovered & they called it immunode ciency virus type2. was made soon after.
The discovery of HIV, the Virus that causes AIDS
In Kenya, the 1st case was noted in 1983 in KNH &
it was noted that the body of the patient had low immunity. From 1981 to date the disease has claimed 22m lives & is still spreading. There is now clear evidence to prove that HIV does cause AIDS. So, in order to nd the source of AIDS, it is necessary to look for the origin of HIV, and nd out how, when and where HIV rst began to cause disease in humans. When and where the HIV virus rst emerged is probably going to remain a mystery for many years to come. While several theories have been put forward, there is no conclusive single agreement on the origin of HIV/AIDS. Some of the mostly acknowledged theories about the origin of HIV include:
Mysterious origins .
The tail of the comet theory
Religious theories (God's wrath and witch craft)
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Monkey origin theories
Conspiracy theories
The calculation theory
1.6.1. Mysterious origins This theory tries to account for the seemingly mysterious origin of HIV by locating it out of this world. It suggests that viral material was carried in the tail gases of a comet passing close to the earth and that this material was deposited, subsequently infecting nearby people. Although famous astronomer's names have been linked to this theory in the popular press, these scientists deny the possibility of this extraterrestrial phenomena and any personal connection to the theory.
1.6.2. Religious Theories (God's wrath and witch craft) Certain segments of the population have openly stated that their belief that AIDS is God's wrath since the Scriptures condemn the homosexual practice in which AIDS was rst observed in the Western world. If one adds to this belief the mysterious origin of the virus, and the apparently hopeless prospects for a cure, it will readily be understood how many have come to believe in Divine intervention, with AIDS being God's way of destroying sinners. If this were so, it would be di cult to see why God, after watching over thousands of years of vastly diering "sins', should suddenly decide to settle His score with homosexuals and drug addicts rather than any other 'sinners'.
The Bible
clearly speaks of a future (and imminent) judgment time when all sinners no matter what their speci c practice will have to pay the penalty for their sins. It does not tell, however, of a God who prejudges particular situations and who picks out special groups for early condemnation. Clearly, there are God-given laws which govern the harmonious interaction of body, mind and spirit. The origin of HIV/A1DS may be traced to an abuse of some of those laws pertaining to the physical and emotional or moral development of man and the presence of sin in the world. It should be recognized that once the process has started, 'guilty' and `innocent' suer alike nowhere is this more obvious or more poignant than in the AIDS pandemic. Rather than its being
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considered a visitation from God, many Africans believe that AIDS is caused by another supernatural power-witchcraft and they use anti-witchcraft rituals and objects to counteract the infection.
1.6.3. Monkey origin theories HIV is a lentivirus that attacks the immune system. Lentiviruses are in turn part of a larger group of viruses known as retroviruses. 'lentivirus' means 'slow virus' because they take such a long time to produce any adverse eects in the body and have been found in a number of dierent animals, including cats, sheep, horses and cattle. The lentivirus of interest in terms of the investigation into the origins of HIV is the Simian Immunode ciency Virus (SIV) that aects monkeys. It is generally thought that HIV is a descendant of a Simian Immunode ciency Virus because certain strains of SIVs bear a very close resemblance to HIV-1 and HIV-2, the two types of HIV For example, HIV-2 corresponds to SIVsm, a strain of the Simian Immunode ciency Virus found in the sooty mangabey (also known as the green monkey), which is indigenous to western Africa.
HIV-1, was until recently more di cult to place.
Until
1999, the closest counterpart that had been identi ed was SIVcpz, found in chimpanzees, but this virus still had certain signi cant dierences from HIV-1. Below are some of the most common theories about how this 'zoonosis' took place, and how SIV became HIV in humans. Zoonosis- viral transfer between animals & humans
• Hunter theory The most commonly accepted theory is that of the 'hunter'. In this scenario, SIVcpz was transferred to humans as a result of chimps being killed and eaten or their blood getting into cuts or wounds on the hunter. Normally the hunter's body would have fought o SIV, but on a few occasions it adapted itself within its new human host and become HIV-1. Discoveries such as this have lead to calls for an outright ban on bush meat hunting to prevent simian viruses being passed to humans.
• Oral Polio Vaccine (OPV) theory That HIV was transferred via medical experiments. That HIV could be traced to the testing of an oral polio vaccine called Chat, given to about a million peo-
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ple in the Belgian Congo, Ruanda and Urundi in the late 1950s. To be reproduced, live polio vaccine needs to be cultivated in living tissue, and Hooper's belief is that Chat was grown in kidney cells taken from local chimps infected with SIVcpz.
This, he claims, would have resulted in the contamination of
the vaccine with chimp SIV, and a large number of people subsequently becoming infected with HIV-1. However, in February 2000 the Wistar Institute in Philadelphia (one of the original places that developed the Chat vaccine) announced that it had discovered in its stores a phial of polio vaccine that had been used as part of the program. The vaccine was subsequently analysed and in April 2001 it was announced that no trace had been found of either HIV or chimpanzee SIV. A second analysis con rmed that only macaque monkey kidney cells, which cannot be infected with SIV or HIV, were used to make Chat. While this is just one phial of many, most have taken its existence to mean that the OPV vaccine theory is not possible. The fact that the OPV theory accounts for just one (group M) of several dierent groups of HIV also suggests that transferral must have happened in other ways too.
The nal
element that suggests that the OPV theory is not credible as the sole method of transmission is the argument that HIV existed in humans before the vaccine trials were ever carried out.
• The contaminated needle vaccine This is an extension of the original 'hunter' theory.
In the 1950s, the use
of disposable plastic syringes became commonplace around the world as a cheap, sterile way to administer medicines.
However, to African healthcare
professionals working on inoculation and other medical programmes, the huge quantities of syringes needed would have been very costly.
It is therefore
likely that one single syringe would have been used to inject multiple patients without any sterilisation in between.
This would rapidly have transferred
any viral particles (within a hunter's blood for example) from one person to another, creating huge potential for the virus to multiply in each new individual it entered, even if the SIV within the original person infected had not yet converted to HIV.
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• The colonialism theory The colonialism or 'Heart of Darkness' theory is one of the more recent theories to have entered into the debate. It is again based on the basic 'hunter' premise, but more thoroughly explains how this original infection could have lead to an epidemic.
During the late 19th and early 20 th century, much of Africa
was ruled by colonial forces. In areas such as French Equatorial Africa and the Belgian Congo, colonial rule was particularly harsh and many Africans were forced into labour camps where sanitation was poor, food was scare and physical demands were extreme. These factors alone would have been su cient to create poor health in anyone, so SIV could easily have in ltrated the labour force and taken advantage of their weakened immune systems to become HIV. A stray and perhaps sick chimpanzee with SIV would have made a welcome extra source of food for the workers.
Moore also believes that many of the
labourers would have been inoculated with unsterile needles against diseases such as smallpox (to keep them alive and working), and that many of the camps actively employed prostitutes to keep the workers happy, creating numerous possibilities for onward transmission.
1.6.4. The conspiracy theory Some say that HIV is a 'conspiracy theory' or that it is 'man-made'. A recent survey carried out in the US for example, identi ed a signi cant number of African Americans who believe HIV was manufactured as part of a biological warfare program, designed to wipe out large numbers of black and homosexual people. Many say this was done under the auspices of the US federal 'Special Cancer Virus Program' (SCVP), possibly with the help of the CIA. Some even believe that the virus was spread (either deliberately or inadvertently) to thousands of people all over the world through the smallpox inoculation program, or to gay men through Hepatitis B vaccine trials.
1.6.5. The calculated theory Opponents of the monkey theories argue that viral sequencing of HIV strains indicate that HIV has been around probably for hundreds of years.
This is
latest theory on the origin of HIV when a team of scientists using computer technology to study the structure of HIV calculated the rate at which the virus
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mutates for the HIV viral sub-bytes to have a common ancestor. This process revealed that HIV originated around 1930 in rural areas of Central Africa, where the virus may have been present for many years in isolated communities. The virus probably did not spread because members of these rural communities had limited contact with people from other areas. But in the 1960s and 1970s, political upheaval, wars, drought, and famine forced many people from these rural areas to migrate to cities to nd jobs. During this time, the incidence of sexually transmitted infections, including HIV infection, accelerated and quickly spread throughout Africa.
As world travel became more prevalent,
HIV infection developed into a worldwide epidemic. Studies of stored blood from the United States suggest that HIV infection was well established there by 1978. Rather than acquiring HIV from SIV it is thought that HIV mutated to become ever more infectious. We will probably never know exactly when and where the virus rst emerged, but what is clear is that sometime in the middle of the 20th century, HIV infection in humans develop and into the epidemic of disease around the world that we now refer to as AIDS.
Example Solution :
.
Describe the dierence Between HIV and AIDS?
HIV is the human immunode ciency virus that causes AIDS (ac-
quired immunode ciency syndrome).
When HIV infects someone, the virus
enters the body and begins to multiply and attack immune cells that normally protect us from disease. It's only when someone with HIV begins to infections and illnesses that they're diagnosed with AIDS.
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Learning Activities Read more papers and journal articles on current advances in HIV/AIDs research. Visit the reproductive health clinic/ section in a hospital around you and get to learn various methods used to control HIV/AIDs and other STIs. Exercise 1.
Revision Questions
Give an account of the limitations of Oral Polio Vaccine Theory as a possible explanation to the origin of HIV? Exercise 2.
Describe the dierence Between HIV and AIDS?
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Assignments 1. Comprehensively discuss the global distribution and trends of HIV/AIDs. Narrow down speci cally to Kenya and use current data and information. 2. Discuss myth associated with HIV/AIDs in your community.
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 2 Sex education and Human sexuality Learning outcomes By the end of this topic you should be able to;
To know what sex education entails
Describe the some of the common STIs
Understand the Myths surrounding sexuality
Understand the relationship between STIs and HIV
Role of sex education as HIV control and management strategy
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2.1. What is sex education? Sex education, also called sexuality education or sex and relationships education.
It's the process of acquiring information and forming attitudes and
beliefs about sex, sexual identity, relationships and intimacy. It is also about developing young people's skills so that they make informed choices about their behavior, and feel con dent and competent about acting on these choices. It is widely accepted that young people have a right to sex education, partly because it is a means by which they are helped to protect themselves against abuse, exploitation, unintended pregnancies, sexually transmitted diseases and HIV/AIDS.
2.1.1. Aims of sex education
To reduce the risks of potentially negative outcomes from sexual behavior like unwanted or unplanned pregnancies and infection with STDs
To enhance the quality of relationships.
To develop young people's ability to make decisions over their entire lifetime.
2.1.2. Myths surrounding sexuality Myths are commonly held believes that are untrue or without foundations. Myths are universal; occurring in almost all cultures and attempts to explain assorted topics on humanity, and may have both religious and non religious dimensions.
The concepts of sex being a necessary evil and the less said
about it the better have led to many misconceptions about sex. Most common sexual myths arise out of ignorance and these circulate more in adolescents and with lack of information they internalize this and practice and this may lead to exposure to HIV/AIDS.
2.2. Sexually Transmitted Diseases Sexually transmitted diseases (STD) are caused by communicable agents (viruses, bacteria, parasites etc) that are principally transmitted during sexual intercourse resulting in clinical illness. How, sometimes infection with these agents does not result in clinical disease but the agents can be transmitted from the
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host organism to their sexual partners. This has given rise to the term sexually transmitted infections (STI). Some persons are thus healthy carriers. There are at least 25 dierent sexually transmitted diseases. What they all have in common is that they can be spread by sexual contact, including vagina, anal and oral sex.
2.2.1. How do you know that you have an STD? Anyone who is sexually active can be at risk from STDs.
Some STDs can
have symptoms, such as genital discharge, pain when urinating and genital swelling and in ammation. Many STDs, such as Chlamydia, can frequently be symptom less. This is why it is advisable to have a sexual health checkup, to screen for STDs, if you think you have been at risk. It can sometimes take a long time for STDs to display any symptoms, and you can pass on any infections during this time, further demonstrating the need to be tested and treated. If you are in a relationship, and are diagnosed with an STD, it does not necessarily mean that your partner has been unfaithful. Symptoms of STDs can present themselves months after infection. Many STDs are very infectious and can cause long-term or permanent damage, including infertility if left untreated. Many STDs can be easily passed onto sexual partners, and some STDs can be passed from a mother to her unborn child too. STDs can also aid the transmission of HIV.
2.2.2. How STDs are transmitted STDs are transmitted by infectious agent microscopic bacteria, viruses, parasites, fungi, and single-celled organisms called protozoa - that thrive in warm, moist environments in the body, such as the genital area, mouth, and throat Most STDs are spread during sexual intercourse (vaginal or anal), but other forms of sexual contact, such as oral sex, can also spread disease. Some STDs are passed from an infected mother to her child before birth, when the infection crosses the placenta and enters the baby's bloodstream; during childbirth, as the baby passes through the birth canal; or after birth, when the baby consumes infected breast milk.
Some viral STDs, especially AIDS, may be
transmitted by blood. Such STDs may be passed between people who share infected needles or received through a transfusion of infected blood. Some peo-
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ple mistakenly believe that STDs can be transmitted through shaking hands or other casual contact, or through contact with inanimate objects such as clothing or toilet seats. Such transmissions are extremely rare.
• Factors that enhance chances of getting infected with STD 1. The potential for sexual activity is greatest from adolescence to the third decade: 15 years and older. The greatest risk occurs in the age group 18-35.
However, the trend is towards very early sexual debut, among
teenagers below 15 years of age, as society changes and liberal attitudes become the norm in formerly traditional societies . 2. Marital status and occupation aect exposure to STDs. Due to industrialization and consequent urbanization; there is usually a large group of single, poorly paid and unemployed young people who live in shanties in towns. Sexual intercourse, for pleasure and for gain, assumes an important role in such circumstances.
Prostitution and promiscuity ourish
under these conditions and so do STDs. Promiscuous sexual behaviour is closely associated with the acquisition and spread of STDs in any group of people.
There are certain factors that may reduce promiscuous be-
haviour in individuals. The more of these factors exist in an individual's life, the less the risk of STDs . 3. Ethnicity is not a risk factor for STDs, but it is closely associated with speci c cultural practices that may predispose to transmission of STDs. In some groups, certain celebrations and rituals (e.g., cleansing after the death of a family member) may involve high-risk sexual practices that predispose individuals to transmission of STIs, such as infection with human immunode ciency virus (HIV), the cause of acquired immunode ciency syndrome (AIDS). A surviving HIV-positive spouse may have to have sex with someone else as part of a ritual . Alternatively, "professional hired cleansers" may infect healthy widows and widowers. Many such funeral events are also associated with much promiscuity as celebrations are held over a week or so with men and women having many opportunities for casual sex. Conversely, societies with strict moral codes regarding sex and marriage have a much lower prevalence of STDs .
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2.2.3. Prevention and Control of STIs One can minimize the risk of getting infected with STIs by having protected sex with condoms and getting tested together with sexual partner(s).
The
more partners one has, the greater the risk of acquiring an STD. Other ways to reduce the risk include using dental dams and condoms during oral sex, clean sex toys after use, clean your hands after having sex, and improving genital hygiene routines.
• Importance of early diagnosis and treatment In many resource poor countries, the approach to diagnosis and treatment of STDs has changed radically in the last few years.
The emphasis is now on
recognition of groups of signs and symptoms, or syndromes, rather than strict etiologic diagnosis based on laboratory ndings as a basis for patient management. Syndromes are based on the clinical presentation of the commonest STDs in the particular country, or region within a country, and patients are treated for the likely STDs that commonly cause that particular combination of signs and symptoms. The commonest cause of urethral discharge in males in Africa, for example, is gonorrhea and Chlamydia urethritis, either individually or in combination. In the new approach, the patient is treated for both infections. Other causes are considered if there is no improvement (Adler, 1996., Holmes, 1990). The advantage of this approach is that even the lowest cadres in the health service can treat patients eectively with a minimum of retraining, without requiring the assistance of a laboratory. The main disadvantage is a certain amount of over-treatment for diseases that are not present, but this is a small price to pay for increased access to STD treatment services for the whole community.
2.2.4. Basic information on some common STDs 1. Bacterial Vaginosis - (BV) is not strictly an STD as it is not transmitted via sexual intercourse. However, it can be exacerbated by sex and is more frequently found in sexually active women than those who have never had intercourse. It is caused by an imbalance in the normal healthy bacteria found in the vagina and although it is relatively harmless and may pass unnoticed, it can sometimes produce an abundance of unpleasant shy
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smelling discharge. Whilst there is no clear explanation as to why BV occurs, there have been suggestions that the alkaline nature of semen could be one cause, as it may upset the acidic nature of the vaginal bacteria. Another cause can be the use of an intrauterine contraceptive device (coil). A woman cannot pass BV to a man, but it is important she receives treatment as BV can occasionally travel up into the uterus and fallopian tubes and cause a more serious infection. Treatment for BV consists of applying a cream to the vagina or taking antibiotics. 2. Balanitis - is often referred to as a symptom of infection, and not necessarily an infection in its own right. It is not strictly an STD, more a consequence of sexual activity. It only aects men and usually presents itself as an in ammation of the head of the penis, and is more common in men who are not circumcised. It can be caused through poor hygiene, irritation due to condoms and spermicides, using perfumed toiletries and by having thrush. It can be prevented through not using certain toiletries and by washing under the foreskin. Treatment can consist of creams to reduce in ammation and antibiotics if necessary. 3. Chlamydia - is the most common treatable bacterial STD. It can cause serious problems later in life if it is not treated. Chlamydia infects the cervix in women. The urethra, rectum and eyes can be infected in both sexes.
Symptoms of infection may show up at anytime.
is between 1 to 3 weeks after exposure.
Often this
However, symptoms may not
emerge until a long way down the line. 4. Crabs or Pubic Lice - are small, crab shaped parasites that live on hair and which draw blood. They live predominantly on pubic hair, but can also be found in hair in the armpits, on the body and even in facial hair such as eyebrows. They can live away from the body too, and therefore can be found in clothes, bedding and towels. You can have crabs and not know about it, but after 2 to 3 weeks, you would expect to experience some itching. Crabs are mainly passed on through body contact during sex, but they can also be passed on through sharing clothes, towels or bedding with someone who has them. There is no eective way to prevent yourself becoming infected, though you can prevent others becoming
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infected by washing clothes and bedding on a hot wash. Lotions can be bought from pharmacies and applied to the body to kill o the parasites. Shaving o pubic hair will not necessarily get rid of crabs. 5. Epididymitis - refers to in ammation of the epididymitis, a tube system above the testicles where sperm are stored. It is not always the result of an STD, but if it is, it is usually due to the presence of Chlamydia or Gonorrhoea. Symptoms will present themselves in the form of swollen and painful testicles and scrotum. The best way of preventing it is to use condoms during sex, as this is the most eective way to prevent Chlamydia and Gonorrhoea.
Epididymitis itself cannot be passed on,
though any other infections that may have caused epididymitis can be passed on (see Chlamydia and Gonorrhoea sections). Treatment usually involves treating the underlying infection with antibiotics. 6. Genital herpes - is caused by the herpes simplex virus. The virus can aect the mouth, the genital area, the skin around the anus and the ngers. Once the rst outbreak of herpes is over, the virus hides away in the nerve bres, where it remains totally undetected and causes no symptoms. Symptoms of the rst infection usually appear one to 26 days after exposure and last two to three weeks. Both men and women may have one or more symptoms, including an itching or tingling sensation in the genital or anal area, small uid- lled blisters that can burst and leave small sores which can be very painful, pain when passing urine, if it passes over any of the open sores and a u-like illness, backache, headache, swollen glands or fever. Find out more about genital herpes. 7. Genital warts - are small eshy growths which may appear anywhere on a man or woman's genital area. They are caused by a virus called the Human Papilloma Virus (HPV). Warts can grow on the genitals, or on dierent parts of the body, such as the hands. After you have been infected with the genital wart virus it usually takes between 1 and 3 months for warts to appear on your genitals. You or your partner may notice pinkish/white small lumps or larger cauli ower-shaped lumps on the genital area.
Warts can appear around the vulva, the penis, the
scrotum or the anus. They may occur singly or in groups. They may
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itch, but are usually painless. Often there are no other symptoms, and the warts may be di cult to see. If a woman has warts on her cervix, this may cause slight bleeding or, very rarely, an unusual coloured vaginal discharge. Find out more about genital warts. 8. Gonorrhoea - is a bacterial infection.
It is sexually transmitted and
can infect the cervix, urethra, rectum, anus and throat. Symptoms of infection may show up at anytime between 1 and 14 days after exposure. It is possible to be infected with gonorrhoea and have no symptoms. Men are far more likely to notice symptoms than women. 9. Gut Infections - can be passed on during sex. Two of the most common infections are Amoebiasis and Giardiasis. They are bacterial infections, and when they reach your gut they can cause diarrhoea and stomach pains. Gut infections can be passed on when having sex with someone who is infected, especially during activities that involve contact with faeces, such as rimming and anal sex. Infection can be prevented through using condoms, dental dams or latex gloves.
Sex toys should be thor-
oughly cleaned after use and hands washed after any contact with faeces. Anti-diarrhoea treatments should be enough to treat most infections, but antibiotics can also be used. 10. Hepatitis - causes the liver to become in amed. There are various different types of hepatitis, the most common being hepatitis A, B and C. Each of these viruses acts dierently. Hepatitis can be caused by alcohol and some drugs, but usually it is the result of a viral infection. Find out more about hepatitis. 11. Molluscum - is a skin disease caused by the Molluscum Contagiosum Virus. It appears as small bumps on the skin, and can last from a couple of weeks to a few years.
Molluscum cause small, pearl-shaped bumps
the size of a freckle on the thighs, buttocks, genitalia and sometimes the face. They are passed on through body contact during sex and through skin-to-skin contact. Transmission can be prevented by using condoms, by avoiding skin-to-skin contact with someone who is infected and by not having sex until they have been treated. In most cases molluscum
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do not need treatment and will disappear over time. However, they can be frozen o or a chemical can be painted on. 12. Non-Speci c Urethritis (NSU) - is an in ammation of a man's urethra. This in ammation can be caused by several dierent types of infection, the most common being Chlamydia. NSU may be experienced months or even in some cases years into a relationship. The symptoms of NSU may include pain or a burning sensation when passing urine, a white/cloudy uid from the tip of the penis that may be more noticeable rst thing in the morning, feeling that you need to pass urine frequently. Often there may be no symptoms, but this does not mean that you cannot pass the infection on to your partner(s). 13. Scabies - is caused by a parasitic mite that can get under the skin and cause itching. The mites are very small and cannot be seen, and many people do not now they have them.
They can cause itching, and this
can start between 2 to 6 weeks after infection.
Signs of infection can
be red lines under the skin of the hands, buttocks and genitals.
The
most common way of becoming infected is through body contact during sex, though it is also possible to be infected through sharing towels and clothes with someone who is infected. This route however is uncommon. There is no eective way to prevent yourself becoming infected, though you can prevent others becoming infected by washing clothes and bedding on a hot wash. Lotions can be bought from pharmacies and applied to the body to kill o the parasites. 14. Syphilis - is not a common infection in the UK but it is more common in some other countries. It is a bacterial infection. It is usually sexually transmitted, but may also be passed from an infected mother to her unborn child. The signs and symptoms of syphilis are the same in both men and women. They can be di cult to recognise and may take up to 3 months to show after having sexual contact with an infected person. Syphilis has several stages. The primary and secondary stages are very infectious. 15. Thrush, also known as Candidiasis - is yeast which lives on the skin and
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is normally kept in check by harmless bacteria. If this yeast multiplies however, it can cause itching, swelling, soreness and discharge in both men and women. Women may experience a thick white discharge and pain when passing urine.
Men may experience the same discharge in
the penis and di culty pulling back the foreskin. Thrush can be passed on when having sex with someone who is infected, but also if you wear too tight nylon or lycra clothes or if you are taking certain antibiotics. Sometimes the cause may be unclear however.
Transmission can be
prevented by using condoms during sex and by men washing underneath their foreskin.
Treatment for thrush involves taking or applying anti
fungal treatments. Thrush can reoccur, especially in women. 16. Trichomonas Vaginosis - also known as Trich is caused by a parasite that is found in women's vagina's and men's urethra's. Often there are not any symptoms.
If symptoms are present, they can include pain when
urinating and discharge in men and discharge, soreness when having sex and when urinating and in ammation of the vulva in women.
Trans-
mission normally occurs through having oral, anal or vaginal sex with an infected person.
Treatment consists of taking antibiotics, and the
infection should not reoccur. 17. AIDS - this is a fatal disease that, once symptoms and signs develop, causes death in less than 2 years (Porth 1998). The virus causing this disease is transmitted most commonly through unprotected sexual intercourse. There is no cure or vaccine, although onset of symptoms can be delayed by the use of antiretroviral drugs. Communities must be taught how to prevent AIDS by limiting sexual activity to one faithful partner. The male and female condoms are an eective method of preventing AIDS and other sexually transmitted diseases when used consistently for casual sexual contacts.
2.2.5. Relationship between HIV and Sexually transmitted infections
STDs enhances HIV transmission by causing open sores and skin injuries in sex organs through which the HIV enters.
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A lot of T-lymphocytes (cells found in the blood and in the lymphatic tissues that ght infections) are mobilized to ght the STD infections and since these are the targets of HIV, a lot of them are infected by HIV and destroyed and the patient goes down faster with the HIV.
The mode of transmission for the STDs is also the same as mode of transmission of HIV.
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Exercise 3.
Revision Questions
Explain any six sexuality myths that have lead to high risk sexual behaviors among youths in Kenya today
Example Solution :
.
Brie y describe the sexual transmission of HIV/AIDS
The risk of transmission through unprotected vaginal sex is thought
to be lower than anal sex, though still highly signi cant. However, where there is a risk of vaginal tears or sores e.g. in the presence of sexually transmitted infection, the risk of transmission is increased signi cantly. HIV transmission through oral sex is a much debated subjected. However, the virus is present in blood and semen, which means that in theory, this is a possible transmission route. There may be an increased risk if there is ejaculation, bleeding gums, lips, or in ammation caused by common throat infections. The sharing of sex toys also carries a risk of HIV transmission. If more than one person is going to use a vibrator or dildo, is essential that it is cleaned thoroughly between uses or covered with afresh condom before each use. .
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References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 3 The Immune system Learning outcomes Upon completing this topic, you should be able to :
Have an overview of the Human Immune system(IS)
Understand various types of immunity
Describe various stages of immune response
What is immunode ciency?
Various disorders and diseases associated with immune system
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3.1. Overview of the Immune System Immune system is a system of biological structures and processes within an organism that protects against diseases by identifying and killing pathogens and tumor cells. The immune system is made up of organs that are involved in ghting invasion by foreign bodies. They include;
3.1.1. The bone marrow The bone marrow is the production site of the white blood cells(WBC) involved in immunity WBC involved includes the B-lymphocytes (B cells) and the T lymphocytes (T cells). The B-lymphocytes mature in the bone marrow and then enter the circulation.
T lymphocytes move from the bone marrow to
the thymus, where they mature into several kinds of cells capable of dierent functions Lymphoid organs The Lymphoid tissues include the thymus gland, the spleen, the lymph nodes, the tonsils and adenoids, and similar tissues in the gastrointestinal, respiratory, and reproductive systems The lymph nodes are distributed throughout the body. They are connected by lymph channels and capillaries, which remove foreign material from the lymph before it enters the bloodstream.
The lymph nodes also serve as centers for immune cell
proliferation. The remaining lymphoid tissues, such as the tonsils and adenoids and other mucoid lymphatic tissues, contain immune cells that defend the body against microorganisms
3.1.2. Types of Immunity
• Innate/ Inborn/Natural/Non-speci c immunity; Present at birth Provide non-speci c immunity to any foreign invador regardless of invadors' composition. Operates under certain mechanisms or factors
Physical/mechanical barrier
Skin protects from entry of pathogens to our body
Respiratory tracts- the hairs /cilia along the tract leads to coughing & sneezing in presence of microorganism hence act as lters to clear the pathogens from upper respiratory tract.
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Biochemical factors Acidic gastric juices e.g.
Hydrochloric acid in the
stomach. Enzymes present in sweat, saliva and breast milk respond by destroying invading microorganisms. Blood protein factors e.g. interferons, compliments, acute phase proteins destroy by puncturing holes in the body.
Genetic - control People may become carriers but not sick
Cellular factors - WBCs participate both in natural & acquired immune responses. The cells ght invading foreign bodies by releasing cell mediators.
Other cells (non-granular) e.g.
phagocytic i.e. sponses.
monocytes & macrophages are
engulf, digest &kill microorganism In ammatory re-
The in ammatory response is a major function of the natu-
ral (nonspeci c) immune system elicited in response to tissue injury or invading organisms. Chemical mediators assist this response by: Minimizing blood loss Walling o the invading organism. Activating phagocytes and promoting formation of brous scar tissues. Regeneration of injured tissue.
• Acquired/ Adaptive / Speci c Immunity Immunologic responses are acquired during life.
Are not present at birth.
They develop as a result of immunization/vaccination. Also developed after contracting a disease i.e. weeks or months after exposure to the disease, the body produces an IR su cient to defend against re-infection. The two types of acquired immunity: active and passive. In active acquired immunity, the immunologic defenses are developed by the person's own body. This immunity generally lasts many years or even a lifetime. Passive acquired immunity is temporary immunity transmitted from another source that has developed immunity through previous disease or immunization.
For example, gamma-
globulin and antiserum, obtained from the blood plasma of people with acquired immunity, are used in emergencies to provide immunity to diseases when the risk for contracting a speci c disease is great and there is not enough time for a person to develop adequate active immunity. Both types of acquired immunity involve humoral and cellular (cell-mediated) immunologic responses. It's divided into 2 forms
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1. Humoral immunity (AMI) Involves antibodies produced by B cells The antibodies recognize & bind speci cally to foreign antigens & may cause one of the following: -Break/ splitdown the membrane of Ag (lysis) -Coat the Ag making it easier for phagocytosis (opsonization) -Neutralize activities of toxins/ virus/ bacteria (neutralization) -Direct killing of foreign Ag ( cytotoxicity / cell killing) -Clump parasites together (agglutination) 2. Cell mediated immunity (CMI) - Two most important T cell subtypes are involved in CMI T helper and T killer cells
• Cells of the Immune System 1. T-Cells T lymphocytes are divided into two major subsets that dier in functions and identity (functionally and phenotypically (identi ably) dierent).
(a) The T helper subset, (CD4+ T cell) - The main function is to augment or potentiate immune responses by the secretion of specialized factors that activate other WBCs to ght o infection.
They in-
teract with B cells or T killer cells & help them respond to foreign agents. T helper1-controls intracellular pathogens (CMI) (b) T helper2 - controls extra cellular pathogens (AMI) b)T killer/suppressor subset (CD8+ T cell). These cells are important in directly killing certain tumor cells, viral-infected cells and sometimes parasites. They directly bind to foreign agents, attack & kill those cells thus eliminating them from the body. The CD8+ T cells are also important in down-regulation of immune responses.
NB: Both types of T cells can be found throughout the body.
They often
depend on the secondary lymphoid organs (the lymph nodes and spleen) as sites where activation occurs, but they are also found in other tissues of the body, most conspicuously the liver, lung, blood, and intestinal and reproductive tracts. 2. Natural Killer Cells (NK) Are similar to the killer T cell subset (CD8+ T cells).
They directly kill certain tumors such as melanomas, lym-
phomas and viral-infected cells, most notably herpes and cytomegalovirus-
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infected cells. NK cells, unlike the CD8+ (killer) T cells, kill their targets without a prior sensitization. But kill more eectively when activated by T h cell. 3. B Cells The major function of B lymphocytes is the production of antibodies in response to foreign proteins of bacteria, viruses, and tumor cells. Antibodies are specialized proteins that speci cally recognize and bind to one particular protein that speci cally recognize and bind to one particular protein.
Antibody production and binding to a foreign
substance or antigen, is critical as a means of signaling other cells to engulf, kill or remove that substance from the body. 4. Granulocytes or Polymorphonuclear (PMN) Leukocytes -It is a group of WBCs.
Granulocytes are composed of three cell types identi ed as
neutrophils, eosinophils and basophils, based on their staining characteristics with certain dyes. These cells are important in the removal of bacteria and parasites from the body. They engulf these foreign bodies and degrade them using their powerful enzymes. (a) Neutrophils -a/c60% - complete dvpt in the BM -enter blood & remain incirculation for 10hours - leave thro capillary wall & enter connective tissue - after a day or 2 they enter the digestive tract or urinary tract & are swept out of the body by waters. (b) Eosinophils a/c 3% of circulating WBCs - help control allergic reactions & helminth infections (c) Basophils- a/c less than 1% - controls allergic reactions, in ammatory reactions, clotting process & fat metabolism 5. Macrophages They are often referred to as scavengers or antigenpresenting cells (APC). This is because they pick up and ingest foreign materials and present these antigens to other cells of the immune system such as T cells and B cells. This is one of the important rst steps in the initiation of an immune response. Stimulated macrophages exhibit increased levels of phagocytosis and are also secretory. Monocytes - they cross capillary wall, enter tissue & dierentiate to macrophages, - destroy bacteria, dead cells and other matters - Are CD4+
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6. Dendritic Cells Dendritic cells function as APCs.
In fact, they are
more e cient APCs than macrophages. These cells are usually found in the structural compartment of the lymphoid organs such as the thymus, lymph nodes and spleen. They are also found in the bloodstream and other tissues of the body. It is believed that they capture antigen or bring it to the lymphoid organs where an immune response is initiated. They are extremely hard to isolate. Recent nding is that dendritic cells bind high amount of HIV, and may be a reservoir of virus that is transmitted to CD4+ T cells during an activation event.
Cells that possess CD4
markers include:
T helper cells
Macrophages
Monocytes
Colon cells
Dendritic cells
Retinal cells
NB: HIV attaches to any CD4+ cell.
Immune response to invasion
When bacteria, viruses or other pathogens overcome the body's natural immunity and gain entry into the blood system, three speci c mechanism of acquired immunity are initiated. They include:
The phagocytic immune response
The humoral or antibody immune response
The cellular or cell mediated immune response
1.
Phagocytic immune response
The rst line of defense, the phagocytic immune response, involves the WBCs (granulocytes and macrophages), which have the ability to ingest foreign particles. These cells move to the point of attack, where they engulf and destroy the invading agents.
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2.
Humoral or Antibody immune response
The humoral response is characterized by production of antibodies by the B-lymphocytes in response to a speci c antigen. Although the B-lymphocyte is ultimately responsible for the production of antibodies, both the macrophages of natural immunity and the special T-cell lymphocytes of cellular immunity are involved in recognizing the foreign substance and in producing antibodies.
3.
Antigen recognition
The part of the invading or attacking organism that is responsible for stimulating antibody production is called an antigen (or an immunogen). For example, an antigen can be a small patch of proteins on the outer surface of the microorganism. A single bacterium, even a single large molecule, such as a toxin (diphtheria or tetanus toxin), may have several such antigens, or markers, on its surface, thus inducing the body to produce a number of dierent antibodies. Once produced, an antibody is released into the bloodstream and carried to the attacking organism. There it combines with the antigen, binding with it like an interlocking piece of a jigsaw puzzle .
3.1.3. Stages in an immune response
• Recognition stage
The immune system's ability to recognize antigens as foreign, or non-self, is the initiating event in any immune response ( g 2.2). The body must rst recognize invaders as foreign before it can react to them. The body accomplishes recognition using lymph nodes and lymphocytes for surveillance. Lymph nodes are widely distributed internally and externally near the body's surfaces. They continuously discharge small lymphocytes into the bloodstream. These lymphocytes patrol the tissues and vessels that drain the areas served by that node.
Lymphocytes are found in the lymph nodes and in the circulating blood. The volume of lymphocytes in the body is impressive. These lympho-
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cytes recirculate from the blood to lymph nodes and from the lymph nodes back into the bloodstream, in a never-ending series of patrols. Some circulating lymphocytes can survive for decades.
Some of these
small, hardy cells maintain their solitary circuits for the lifetime of the person.
The exact way in which circulating lymphocytes recognize antigens on foreign surfaces is not known; however, theorists think that recognition depends on speci c receptor sites on the surface of the lymphocytes. Macrophages play an important role in helping the circulating lymphocytes process the antigens.
When foreign materials enter the body, a
circulating lymphocyte comes into physical contact with the surfaces of these materials.
Upon contact, the lymphocyte, with the help of
macrophages, either removes the antigen from the surface or in some way picks up an imprint of its structure, which comes into play with subsequent re-exposure to the antigen.
In a streptococcal throat infection, for example, the streptococcal organism gains access to the mucous membranes of the throat. A circulating lymphocyte moving through the tissues of the neck comes in contact with the organism. The lymphocyte, familiar with the surface markers on the cells of its own body, recognizes the antigens on the microbe as dierent (non-self ) and the streptococcal organism as antigenic (foreign).
This
triggers the second stage of the immune responseproliferation.
• Proliferation stage
The circulating lymphocyte containing the antigenic message returns to the nearest lymph node.
Once in the node, the sensitized lympho-
cyte stimulates some of the resident dormant T and-lymphocytes to enlarge, divide, and proliferate. T lymphocytes dierentiate into cytotoxic (or killer) T cells, whereas-lymphocytes produce and release antibodies. Enlargement of the lymph nodes in the neck in conjunction with a sore throat is one example of the immune response.
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• Response stage
In the response stage, the changed lymphocytes function either in a humoral or a cellular fashion.
The production of antibodies by the-
lymphocytes in response to a speci c antigen begins the humoral response. Humoral refers to the fact that the antibodies are released into the bloodstream and so reside in the plasma ( uid fraction of the blood).
With the initial cellular response, the returning sensitized lymphocytes migrate to areas of the lymph node (other than those areas containing lymphocytes programmed to become plasma cells). Here, they stimulate the residing lymphocytes to become cells that will attack microbes directly rather than through the action of antibodies. These transformed lymphocytes are known as cytotoxic (killer) T cells. The T stands for thymus, signifying that during embryologic development of the immune system, these T lymphocytes spent time in the thymus of the developing fetus, where they were genetically programmed to become T lymphocytes rather than the antibody-producing-lymphocytes. Viral rather than bacterial antigens induce a cellular response.
This response is manifested
by the increasing number of T lymphocytes (lymphocytosis) seen in the blood smears of people with viral illnesses, such as infectious mononucleosis.
Most immune responses to antigens involve both humoral and cellular responses, although one usually predominates. For example, during transplantation rejection, the cellular response predominates, whereas in the bacterial pneumonias and sepsis, the humoral response plays the dominant protective role.
• Eector stage
In the eector stage, either the antibody of the humoral response or the cytotoxic (killer) T cell of the cellular response reaches and couples with the antigen on the surface of the foreign invader. The coupling initiates a series of events that in most instances results in the total destruction of the invading microbes or the complete neutralization of the toxin. The events involve interplay of antibodies (humoral immunity), complement, and action by the cytotoxic T cells (cellular immunity).
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Production of B-Lymphocytes
B-lymphocytes stored in the lymph nodes are subdivided into thousands of clones, each responsive to a single group of antigens having almost identical characteristics.
When the antigenic message is carried back
to the lymph node, speci c clones of the-lymphocyte are stimulated to enlarge, divide, proliferate, and dierentiate into plasma cells capable of producing speci c antibodies to the antigen. Other-lymphocytes differentiate into-lymphocyte clones with a memory for the antigen. These memory cells are responsible for the more exaggerated and rapid immune response in a person who is repeatedly exposed to the same antigen.
3.1.4. Role of antibodies in Humoral Immune Responses
Antibodies are large proteins called immunoglobulins because they are found in the globulin fraction of the plasma proteins.
Each antibody
molecule consists of two subunits, each of which contains a light and a heavy peptide chain. The sub-units are held together by a chemical link composed of disul de bonds. Each subunit has a portion that serves as a binding site for a speci c antigen referred to as the Fab fragment. This site provides the "lock" portion that is highly speci c for an antigen. An additional portion, known as the Fc fragment, allows the antibody molecule to take part in the complement system.
Antibodies defend against foreign invaders in several ways, and the type of defense employed depends on the structure and composition of both the antigen and the immunoglobulin. The antibody molecule has at least two combining sites, or Fab fragments. One antibody can act as a crosslink between two antigens, causing them to bind or clump together. This clumping eect, referred to as agglutination, helps clear the body of the invading organism by facilitating phagocytosis. Some antibodies assist in removing oending organisms through opsonization. In this process, the antigenantibody molecule is coated with a sticky substance that also facilitates phagocytosis.
Antibodies also promote the release of vasoactive substances, such as histamine and slow-reacting substance, two of the chemical mediators
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of the in ammatory response.
In addition, antibodies are involved in
activating the complement system.
3.1.5. Types of Immunoglobulins The body can produce ve dierent types of immunoglobulins. (Immunoglobulins are commonly designated by the abbreviation Ig.) Each of the ve types, or classes, is identi ed by a speci c letter of the alphabet (IgA, IgD, IgE, IgG, and IgM). Classi cation is based on the chemical structure and biologic role of the individual immunoglobulin.
The following list summarizes some out-
standing characteristics of the immunoglobulins:
IgG (75% of Total Immunoglobulin) (interstitial uid) tions
Appears in serum and tissues
Assumes major role in blood borne and tissue infec-
Activates complement system Enhances phagocytosis Crosses
placenta
IgA (15% of Total Immunoglobulin)
Appears in body uids (blood,
saliva, tears, breast milk, and pulmonary, gastrointestinal, prostatic, and vaginal secretions)
Protects against respiratory, gastrointestinal, and
genitourinary infections
Prevents absorption of antigens from food
Passes to neonate in breast milk for protection
IgM (10% of Total Immunoglobulin) serum
Activates complement system
IgD (0.2% of Total Immunoglobulin) serum
Appears mostly in intravascular
Appears as the rst immunoglobulin produced in response to
bacterial and viral infections
Appears in small amounts in
Possibly in uences B-lymphocyte dierentiation, but plays un-
clear role
IgE (0.004% of Total Immunoglobulin)
Appears in serum
in allergic and some hypersensitivity reactions
Takes part
Combats parasitic in-
fections
3.1.6. Cellular (or cell mediated) immune response
It is called cellular because it involves production of special cells T lymphocytes (or T cells) that are primarily responsible for cellular immu-
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Figure 3.1: Cellular (or cell mediated) immune response
nity. These lymphocytes spend time in the thymus, where they are programmed to become T cells rather than antibody-producinglymphocytes (Figure 2.3). Several types of T cells exist, each with designated roles in the defense against bacteria, viruses, fungi, parasites, and malignant cells. T cells attack foreign invaders directly rather than by producing antibodies.
Cellular reactions are initiated by the binding of an antigen with an antigen receptor located on the surface of a T cell. This may occur with or without the assistance of macrophages. The T cells then carry the antigenic message, or blueprint, to the lymph nodes, where the production of other T cells is stimulated. Some T cells remain in the lymph nodes and retain a memory for the antigen.
Other T cells migrate from the
lymph nodes into the general circulatory system and ultimately to the tissues, where they remain until they either come in contact with their respective antigens or die.
• Role of T lymphocytes Two major categories of eector T cells are helper T cells and cytotoxic T cells. These cells participate in destroying foreign organisms. Other T cells include suppressor T cells and memory T cells. T cells interact closely withcells, indicating that humoral and cellular immune responses are not separate,
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unrelated processes but rather branches of the immune response that can and do aect each other. 1. Helper T cells (helper CD4 cells) are activated upon recognition of antigens and stimulate the rest of the immune system.
When activated,
helper T cells secrete cytokines that attract and activate-cells, cytotoxic T cells, natural killer cells, macrophages, and other cells of the immune system (Laurence J. 1995).
Separate subpopulations of helper T cells
produce dierent types of cytokines and determine whether the immune response will be the production of antibodies or a cell-mediated immune response. Helper T cells produce lymphokines, one category of cytokines. These lymphokines activate other T cells (interleukin-2, or IL-2), natural and cytotoxic T cells (interferon-gamma), and other in ammatory cells (tumor necrosis factor).
Helper T2 cells produce IL-4 and IL-5, lym-
phokines that activate-cells to grow and dierentiate (Laurence J. 1995, Roit I; et al 1989)). 2. Cytotoxic T cells (killer T cells) attack the antigen directly by altering the cell membrane and causing cell lysis (disintegration) and releasing cytolytic enzymes and cytokines.
Lymphokines can recruit, activate,
and regulate other lymphocytes and WBCs. These cells then assist in destroying the invading organism. 3. Suppressor T cells, has the ability to decrease B-cell production, thereby keeping the immune response at a level that is compatible with health (e.g. su cient to ght infection adequately without attacking the body's healthy tissues). Memory T cells are responsible for recognizing antigens from previous exposure and mounting an immune response.
• Roles of null lymphocytes and natural killer cells in cellular immune responses Null lymphocytes and natural killer (NK) cells are other lymphocytes that assist in combating organisms. These are distinct from-cells and T cells and lack the usual characteristics of-cells and T cells. 1. Null lymphocytes, a subpopulation of lymphocytes, destroy antigens already coated with antibody. These cells have special Fc receptor sites on
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their surfaces that allow them to couple with the Fc end of antibodies (antibody-dependent, cell-mediated cytotoxicity, Beattie, T et al 2002). 2. Natural killer cells, another subpopulation of lymphocytes, defend against microorganisms and some types of malignant cells. NK cells are capable of directly killing invading organisms and producing cytokines. The helper T cells contribute to the dierentiation of null and NK cells (Laurence J. 1995).
3.1.7. Complement System
Circulating plasma proteins, which are made in the liver and activated when an antibody couples with its antigen, are known as complement. These proteins interact sequentially with one another in a cascade or "falling domino" eect. This complement cascade alters the cell membranes on which antigen and antibody complex form, permitting uid to enter the cell and leading eventually to cell lysis and death. In addition, activated complement molecules attract macrophages and granulocytes to areas of antigen antibody reactions. These cells continue the body's defense by devouring the antibody-coated microbes and by releasing bacterial agents.
Complement plays an important role in the immune response. Destruction of an invading or attacking organism or toxin is not achieved merely by the binding of the antibody and antigens; it also requires activation of complement, the arrival of killer T cells, or the attraction of macrophages.
3.2. Immunode ciency
When some or one of the components of the immune system is lacking, disorders or abnormalities arises and this is referred to as an immunode ciency. These abnormalities or disorders are either as a result of genetic abnormally (congenital) or are acquired within the course of life due to a number of factors
Old age
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Nutrition
Autoimmune disorder
Neoplastic disease
Chronic illness and surgery
Medication
Lifestyle and other factors
Stress
1. Age - People at the extremes of the lifespan are more likely to develop problems related to immune system functioning than are those in their middle years. Frequency and severity of infections are increased in elderly people, possibly from a decreased ability to respond adequately to invading organisms. Both the production and the function of T and B -lymphocytes may be impaired. The incidence of autoimmune diseases also increases with aging, possibly from a decreased ability of antibodies to dierentiate between self and non-self. Failure of the surveillance system to recognize mutant, or abnormal, cells may be responsible for the high incidence of cancer associated with increasing age. 2. Declining function of various organ systems associated with increasing age also contributes to impaired immunity. Decreased gastric secretions and motility allow normal intestinal ora to proliferate and produce infection, causing gastroenteritis and diarrhea.
Decreased renal circula-
tion, ltration, absorption, and excretion contribute to risk for urinary tract infections. Moreover, prostatic enlargement and neurogenic bladder can impede urine passage and subsequently bacterial clearance through the urinary system. Urinary stasis, common in elderly people, permits the growth of organisms. Exposure to tobacco and environmental toxins impairs pulmonary function.
Prolonged exposure to these agents
decreases the elasticity of lung tissue, the eectiveness of cilia, and the ability to cough eectively.
These impairments hinder the removal of
infectious organisms and toxins, increasing the elderly person's susceptibility to pulmonary infections and cancers.
Finally, with aging, the
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skin becomes thinner and less elastic.
Peripheral neuropathy and the
accompanying decreased sensation and circulation may lead to stasis ulcers, pressure ulcers, abrasions, and burns.
Impaired skin integrity
predisposes the aging person to infection from organisms that are part of normal skin ora. 3. Nutrition - Adequate nutrition is essential for optimal functioning of the immune system. Vitamin intake, essential for DNA and protein synthesis, if inadequate, may lead to protein-calorie de ciency and subsequently to impaired immune function.
Vitamins also help in the regulation of
cell proliferation and maturation of immune cells. Excess or de ciency of trace elements (i.e., copper, iron, manganese, selenium, or zinc) in the diet generally suppresses immune function.
Fatty acids are the build-
ing blocks that make up the structural components of cell membranes. Lipids are precursors of vitamins A, D, E, and K as well as cholesterol. Both excess and de ciency of fatty acids have been found to suppress immune function. 4. Depletion of protein reserves results in atrophy of lymphoid tissues, depression of antibody response, reduction in the number of circulating T cells, and impaired phagocytic function. infection is greatly increased.
As a result, susceptibility to
During periods of infection and serious
illness, nutritional requirements may be exaggerated further, potentially contributing to depletion of protein, fatty acid, vitamin, and trace elements and an even greater risk of impaired immune response and sepsis.
3.2.1. Autoimmune disorders In general, autoimmune disorders are more common in females than in males. This is believed to be the result of the activity of the sex hormones. The ability of sex hormones to modulate immunity has been well established. There is evidence that estrogen modulates the activity of T lymphocytes (especially suppressor cells), whereas androgens act to preserve IL-2 production and suppressor cell activity. The eects of sex hormones on B -cells are less pronounced. Estrogen activates the autoimmune-associated B-cell population that expresses the CD5 marker (an antigenic marker on the-cell). Estrogen tends to enhance
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immunity, whereas androgen tends to be immunosuppressive.Autoimmune disorders include lupus erythematosus, rheumatoid arthritis, or psoriasis
3.2.2. Neoplastic disease Immunosuppression contributes to the development of cancers; however, cancer itself is immunosuppressive.
Large tumors can release antigens into the
blood, and these antigens combine with circulating antibodies and prevent them from attacking the tumor cells. Furthermore, tumor cells may possess special blocking factors that coat tumor cells and prevent destruction by killer T lymphocytes. During the early development of tumors, the body may fail to recognize the tumor antigens as foreign and subsequently fail to initiate destruction of the malignant cells. Hematologic cancers, such as leukemia and lymphoma, are associated with altered production and function of WBCs and lymphocytes. All treatments that an individual has received or is currently receiving, such as radiation or chemotherapy, are vital. Radiation destroys lymphocytes and decreases the population of cells required to replace them. The size or extent of the irradiated area determines he extent of Immunosuppression. Whole-body irradiation may leave the patient totally immunosuppressed. Chemotherapy also destroys immune cells and causes Immunosuppression.
3.2.3. Chronic illness and surgery
Chronic illness may contribute to immune system impairments in various ways.
Renal failure is associated with a de ciency in circulating
lymphocytes. In addition, immune defenses may be altered by acidosis and uremic toxins. In diabetes, an increased incidence of infection has been associated with vascular insu ciency, neuropathy, and poor control of serum glucose levels. Recurrent respiratory tract infections are associated with chronic obstructive pulmonary disease as a result of altered inspiratory and expiratory function and ineective airway clearance. Additionally, surgical removal of the spleen, lymph nodes, or thymus or organ transplantation may place an individual at risk for impaired immune function.
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3.2.4. Special problems
Conditions such as burns and other forms of injury and infection may contribute to altered immune system function.
Major Burns or other
factors cause impaired skin integrity and compromise the body's rst line of defense. Loss of large amounts of serum with burn injuries depletes the body of essential proteins, including immunoglobulins. The physiologic and psychological stressors associated with surgery or injury stimulates cortisol release from the adrenal cortex; increased serum cortisol also contributes to suppression of normal immune responses.
1. Medications
In large doses, antibiotics, corticosteroids, cytotoxic agents, salicylates, nonsteroidal anti-in ammatory drugs, and anesthetics can cause immune suppression.
2. Lifestyle and Other Factors
Like any other body system, the immune system functions depend on the function of other body systems. Poor nutritional status, smoking, excessive consumption of alcohol and exposure to environmental radiation and pollutants have been associated with impaired immune function.
3.2.5. Role of immune system in HIV pathogenesis
The immune system is responsible for body defense against attack from pathogenesis
It is made up of white blood cells which include granulocytes such as neutrophils and basophils, and agranulocytes such as monocytes and lymphocytes.
T-helper lymphocytes have a CD4+ marker that the HIV use for entry into the cell and replicates
T-helper lymphocytes are important in immune regulation because when they are activated they recruit other immune cell involved in immune responses.
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HIV uses the CD4+ cells to replicate and produce more viral particles.
CD4 are killed and destroyed as viral production progresses
Cytotoxic T-lymphocytes with CD8+ marker target any virally infected CD4+ cells and kills them
Macrophages which have a CD4+ marker too act as reservoir and are also killed by cytotoxic
As virtually infected cells are killed by cytotoxic T-lymphocytes and more of the CD4+ cells destroyed as a result of viral replication, their numbers goes down.
The immune system is depleted of these crucial cells involved in body defense and becomes vulnerable to attack by opportunistic pathogens.
Example Solution :
.
Brie y describe the sexual transmission of HIV/AIDS
The risk of transmission through unprotected vaginal sex is thought
to be lower than anal sex, though still highly signi cant. However, where there is a risk of vaginal tears or sores e.g. in the presence of sexually transmitted infection, the risk of transmission is increased signi cantly. HIV transmission through oral sex is a much debated subjected. However, the virus is present in blood and semen, which means that in theory, this is a possible transmission route. There may be an increased risk if there is ejaculation, bleeding gums, lips, or in ammation caused by common throat infections. The sharing of sex toys also carries a risk of HIV transmission. If more than one person is going to use a vibrator or dildo, is essential that it is cleaned thoroughly between uses or covered with afresh condom before each use. .
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Exercise 4.
Revision Questions
Discuss the role of immune system in HIV pathogenesis
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References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 4 Biology of HIV Learning outcomes By the end of this topic you should be able to;
To know the nature of HIV
Describe the structure of HIV
Understand the Life cycle of HIV
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4.1. Nature of HIV HIV can't grow or reproduce on its own. It requires cell of living organisms to infect & reproduce. HIV is speci c to CD4+ cells in the human body i.e. cells with surface molecule called Cluster of Dierentiation 4. ing this molecule are called CD4+ cells.
Cells carry-
Therefore HIV cant survive in the
animal blood, because its only human blood that contains CD4+cells. HIV is a lentivirus.
Like all viruses in this group it attacks the immune system.
Lentiviruses are in turn part of a larger group of viruses called retroviruses. The term "retrovirus" stems from the fact that these kinds of viruses are capable of copying RNA into DNA. The name lentivirus means slow virus. This is because they take such a longtime to produce any adverse eects in the body.
4.2. The Structure of HIV Outside of a human cell, HIV exists as roughly spherical particles (sometimes called virions). The surface of each particle is studded with lots of little spikes. An HIV particle is around 100-150 billionths of a meter in diameter. That's about the same as 0.1 microns or 4 millionths of an inch or one seventieth of the diameter of a human CD4+ white blood cell.
Unlike most bacteria,
HIV particles are much too small to be seen through an ordinary microscope. However they can be seen clearly with an electron microscope.
NB: The proteins gp120 and gp41 together make up the spikes that project from HIV particles, while p17 forms the matrix and p24 forms the core. Structurally HIV consist of 1.
The viral envelope -
HIV has a diameter of 1/10,000 of a millimeter
and is spherical in shape.
The outer coat of the virus, known as the
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viral envelope, is composed of two layers of fatty molecules called lipids, taken from the membrane of a human cell when a newly formed virus particle buds from the cell. Embedded in the viral envelope are proteins from the host cell as well as 72 copies (on average) of a complex HIV protein (frequently called "spikes") that protrudes through the surface of the virus particle (virion).
This protein, known as Env, consists of
a cap made of three molecules called glycoprotein (gp) 120, and a stem consisting of three gp41 molecules that anchor the structure in the viral envelope.
Much of the research to develop a vaccine against HIV has
focused on these envelope proteins. 2.
Viral core/capsid - The viral core (or capsid) is usually bullet-shaped and is made from the protein P24. The core contains:
(a) Two copies of identical strands of RNA - HIVs' genetic material i. Almost all organisms, including most viruses, store their genetic material on long strands of DNA. ii. Retroviruses are the exception because their genes are composed of RNA (Ribonucleic Acid). iii. RNA has a very similar structure to DNA. However, small differences between the two molecules mean that HIV's replication process is a bit more complicated than that of most other viruses. (b) Three viral enzymes: required for HIV replication
Reverse transcriptase (RT)- converts viral RNA to ds DNA
Integrase- integrates DNA produced by RT into human DNA
Protease/proteinase- cuts proteins into segments & facilitates assemblance of new viral copies.
3.
Matrix - Just below the viral envelope is a layer called the matrix, which is made from the protein p17 which maintains the integrity of the virus structure & transport genetic material.
4.
Double layered lipid envelope 55
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HIV particles surround themselves with a coat of fatty material known as the viral envelope (or membrane).
Projecting from this are around 72 little spikes, which are formed from the proteins gp120 which protrudes from the surface & binds CD4+ cells and gp41. which is embedded within the envelope & is for entry/fusion.
4.3. The Life Cycle of HIV/ HIV Replication 1.
Attachment
- The gp120 on the surface of the virus particle bind to
the CD4 receptor on the surface of human T cell and the viral envelope fuses with the human T cell membrane. 2.
Entry - The contents of the HIV particle are then released into the cell, leaving the envelope behind.
3.
Reverse Transcription - Once inside the cell, the HIV enzyme reverse transciptase converts the viral RNA into DNA, which is compatible with human genetic material(DNA)
4.
Integration
- This DNA is transported to the cell's nucleus, where it
is spliced into the human DNA by the HIV enzyme integrase.
Once
integrated, the HIV DNA is known as provirus. 5.
Transcription - HIV provirus may lie dormant within a cell for a long time. But when the cell becomes activated, it treats HIV genes in the same way as human genes. First it converts them into messenger RNA (using human enzymes).
6.
Translation - Then the messenger RNA is transported outside the nucleus, and is used as a blueprint for producing new HIV proteins and enzymes.
7.
Assembly & Budding
- Among the strands of messenger RNA pro-
duced by the cell are complete copies of HIV genetic material.
These
gather together with newly made HIV proteins and enzymes to form new viral particles, which are then released from the cell. The enzyme
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protease plays a vital role at this stage of HIV's life cycle by chopping up long strands of protein into smaller pieces, which are used to construct mature viral cores. 8.
Maturation & release
- The newly matured HIV particles are ready
to infect another cell and begin the replication process all over again. In this way the virus quickly spreads through the human body. And once a person is infected, they can pass HIV on to others in their bodily uids.
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Exercise 5.
Revision Questions
Discuss the life cycle of HIV.
Example Solution :
.
Are there other ways to avoid getting HIV through sex?
The male condom is the only widely available barrier against sexual
transmission of HIV. Female condoms are fairly unpopular in the U.S. and still relatively expensive, but they are gaining acceptance in some developing countries. Eorts are also under way to develop topical creams or gels called "microbicides," which could be applied prior to sexual intercourse to kill HIV and prevent other STIs that facilitate HIV infection.
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Revision questions or guidelines 1. The knowledge of HIV life cycle has advanced the ght against HIV through designing of antiretroviral drugs. Using appropriate examples, discuss this statement. 2. Control of HIV/AIDs is directly linked to the knowledge of the transmission of the causative agent. Discuss in detail this statement. 3. The use of antiretroviral drugs is facing various challenges.
Highlight
and brie y discuss the major limitation to the use of ARVs. 4. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 5 Disease progression and symptoms Learning outcomes Upon completing this topic, you should be able to understand:
Stages of HIV infection
Factors that leads to faster progression fro HIV to full blown AIDs
Opportunistic infections
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5.1. Introduction HIV infects cells of the immune system and the central nervous system. The main cell HIV infects is T helper cell which is a crucial part of the immune system, because it co-ordinates the actions of other cells of the immune system. A large reduction in the number of T helper cells seriously weakens the immune system.
5.1.1. Exposure vs. Infection When HIV+ individual encounters an uninfected person, this does not always result in transmission of HIV to the uninfected person. Only a fraction of the exposed people will be infected. Dierent kinds of exposure between infected & uninfected individuals have dierent probabilities of leading to infection. Those who are exposed & become infected do not show sign of illnesses right away.
5.1.2. Infection vs. Disease Among individuals who become infected with HIV, not everybody will develop physical symptoms. Most viral infections don't show physical symptoms, but most people infected with HIV ultimately develop some disease symptoms. These disease symptoms are caused by damage or destruction of cells & tissues in the infected person.
In some cases the damage may result from direct
killing of cells by virus. In the case of AIDS, most of physical symptoms are the indirect result of damage to the immune system by HIV. Factors such as age, sex, genetic make-up, nutrition, environmental factors,& encounters with other infectious agents can in uence the exact nature of the symptoms in a particular individual.
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5.2. Stages of HIV Infection There are four stages of HIV infection and they include: 1. Primary H IV infection, window period & sero conversion 2. Clinically asymptomatic stage, 3. Symptomatic HIV infection, 4. Progression from HIV to AIDS.
5.2.1. Primary HIV infection This is the initial stage where one obtains the virus through the various modes of transmission. It can be divided into: 1.
Window period - This stage of infection lasts for a few weeks to about 3 months and is often accompanied by a short u-like illness or no signs. HIV cannot be detected in blood screening although HIV is present in blood & the blood in not 100% free of HIV. The virus cannot be seen in the rst 21 days. During this time a person can still transmit the virus to another person. It is the most crucial stage.
2.
Sero conversion
- This is the development of the anti-bodies.
Im-
mune system begins to respond to HIV by producing HIV antibodies and cytotoxic lymphocytes. If an HIV antibody test is done before seroconversion is complete then it may not be positive.
In this stage a
person may have u like illnesses, fever, fatigue, sore throat, joint pains & lymphadenopathy Some will not experience any illnesses at this stage.
5.2.2. Clinical asymptomatic HIV infection/ Latent phase The presence of HIV without major symptoms. Although there may be swollen glands.
The level of HIV in the peripheral blood drops to very low levels
but people remain infectious. HIV antibodies are detectable in the blood, so antibody tests will show a positive result.
HIV is not dormant during this
stage, but is very active in the lymph nodes. Large amounts of T helper cells are infected and die and a large amount of virus is produced. This period can last for many years (5 15 years)
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• Initial Infection Symptoms include:
Mononucleosis-like illness (sore throat, swollen glands, fever) & skin rash
Encephalopathy i.e. Brain infections - brain swelling & in ammation of the brain lining or meninges
This causes headache, fever, brain functions impairment, di culty in concentration, remembering or solving problems
Personality changes may also occur
NB: Asymptomatic period some type of balance exist between HIV infection & the immune system in the infected person
5.2.3. Symptomatic HIV infection/AIDS Related Complex (ARC) phase Over time the immune system loses the struggle to contain HIV due to the following main reasons: 1. The lymph nodes and tissues become damaged or 'burnt-out' because of the years of activity; 2. HIV mutates and becomes more pathogenic, i.e.
stronger and more
varied, leading to more T helper cell destruction; 3. The body fails to keep up with replacing the T helper cells that are lost. As the immune system fails, so symptoms develop. Initially many of the symptoms are mild, but as the immune system deteriorates the symptoms worsen. When the viral load reaches a critical amounts, the immune system is suppressed to such a degree that other infections which under normal circumstances will not be di cult to resist gain entrance i.e. opportunistic infections. Opportunistic infections they take advantage of the impairment of the immune system & sometimes are caused by organisms that don't cause infections/ diseases in man. Symptoms of HIV infection in this stage.
Two or more of the following signs /
symptoms may occur:
Chronic fever
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Lethargy (fatigue/ tiredness)
Continuous diarrhea - Eczema (allergy of the face)
More than 10% weight loss - Psoriasis (itchy pimples)
Lymphadenopathy
Dermatitis (itchy skin)
Night sweats
Oral candidiasis (sores in mouth)
Dementia (short term memory loss)
Incubation period
- is the length in time between initial infection &
becoming symptomatic. It varies between people & depends on a length of factors
5.2.4. Progression of HIV to AIDS As the immune system becomes more and more damaged the illnesses that present become more and more severe leading eventually to an AIDS diagnosis. It's the most advanced stage of HIV infection.
At this time when CD4 cell
count has gone down below 200 CD4 cells/ml, HIV develops to one or more severe opportunistic infections or cancer. The infection / cancer may be life threatening due to the weakened immune system.
Common symptoms in this stage/ Initial Disease Symptoms An infected individual may have symptoms from more than one of these classes; 1. HIV wasting syndrome:
- Sudden unexplained loss in body weight (
>10% of total body weight), unexplained chronic diarrhea (>1 month), Chronic weakness, unexplained prolonged fever usually at night that causes night sweats (>1 month) and brain damage due to high temp that causes fevers 2. Lymphadenopathy syndrome (LAS)/ persistent generalized lymphadenopathy (PGL): Lymph glands enlargement is persistent. They swell in groin, armpits, head & neck but are not painful. Some infected people may experience both LAS & Wasting Syndrome
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3. Neurologic disease - direct damage of the brain by HIV or by other agent. Damage of parts of the nervous system can also cause dierent neurologic symptoms. For example:
(a) Dementias - Impaired mental functions, forgetfulness, loss of mental functions. Di culty reasoning & performing mental tasks. Depression, social withdrawals & personality changes. Unable to care for themselves eventually. Coma & death may follow. (b) Spinal cord damage/ swelling (myelopathy) - Spinal cord transmits nerve impulses to the muscles of the body. Because of this, damage may result in weaknesses or paralysis of voluntary muscles/ limbs. (c) Peripheral nerve swelling/ damage (neuropathy) - these nerves sense pain. When damaged can cause burning or stinging sensations in the hands or feet or occurrence of numbness
NB:
individual patients may experience a mixture of any of these ill-
nesses Others include:
Coughs & gasping of breath, Seizure- lack of
coordination, Di culty or pain during swallowing, Psychotic symptoms - mental confusion & forgetfulness, Loss of vision, Severe headache, Nausea, Abdominal crump & vomiting, Extreme fatigue, Cancers-m of blood, and Coma. HIV+ patient can die any moment at this stage.
5.2.5. Other Complications in HIV Patients This manifest when immune system is weak and they include:
a)
Common brain infections - Tumors, Swelling of the brain, Nerve damage. They can cause Headache & confusion, Poor coordination of feet, Blindness, Enlarged lymph nodes, Fever, sore throat, weaknesses
b)
Common skin infections - When immune system is damaged in HIV patients the skin conditions tend to persist more & they become di cult to treat. In most cases these conditions are caused by bacteria, viruses or fungi.
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5.2.6. Factors that lead to faster development of HIV infection to full- blown AIDs 1.
Age - Persons who get infected after the age of 35years move faster from HIV infection to full blown AIDS than those who get infected in their mid 20s. Children who get infected at birth die faster simply because their immune system is not well developed at their tender age.
2.
Type of HIV contracted
- There are two well known types: HIV1
and HIV2. HIV1 is harsher on people hence kills faster than HIV2. 3.
Mode of transmission - HIV got through blood transfusion kills faster than one got through sexual contact. This is because the amount of virus channeled into the bloodstream is in large quantity.
4.
Ill - health & other types of infections
- People who are already
sick & then get infected move faster than those infected when healthy. Tropical diseases such as malaria, typhoid & intestinal worms makes patients to develop AIDS faster 5.
Nutritional status
- Those infected & are not eating enough of well-
balanced foods are more likely to develop AIDS faster 6.
Lifestyle
- People who expose themselves to re-infection with other
strains of HIV or STIs / STDs and other illnesses move faster from HIV to AIDS 7.
Opportunistic infections
- If they are not competently treated, then
the HIV+ person develops AIDS faster.
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5.3. Opportunistic Infections 1. Examples of fungal infections
(a) PCP - In ammation of the lungs caused by infection with fungus called Pneumocystis carinii. In amed areas of lungs appear as white spots in x-rays. It's the leading cause of death in AIDS patients i.e. about 50% of AIDS patients will eventually develop PCP (b) Candida - Fungus is similar to baker's yeast. & mucosal surfaces (mouth, vagina). white plaques that feel furry.
It is found on skin
In mouth they appear like
Antifungal e.g.
mycostatin can be
used. They are di cult to completely eliminate. They can spread to oesophagus & cause painful burning sensation when eating i.e. oesophagitis. 50% of AIDS patients will experience candidacies. (c) Systemic mycosis - Soil fungus that can cause generalized infections in AIDS patients. Exist in either mold like or yeast like form & are called dimorphic.
There are of 3 types - Histoplasmosis, Coccid-
iomycosis, & Cryptococcus. They cause lung infections in healthy patients. In AIDS patients, the brain, skin, bone, liver & lymphatic tissue may also be highly infected.
2. Example of Bacterial infections - Components of I.S. responsible for controlling the common bacteria are less aected by HIV infection, thus adult AIDS patients do not generally suer infections with common bacteria
(a) Mycobacterium - Infection with Mycobacterium avium intracellular is most common in AIDS patients.
It does not cause disease in
healthy people but it causes TB-like disease in the lungs of AIDS patients.
Also causes infection of BM & presence of bacteria in
blood at high levels. Patients will have fevers & low no. of white blood cells.
Mycobacterium tuberculosis that causes TB is also
common in AIDS patients.
3. Example of Viral infections
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(a) Cytomegalovirus (CMV) - Common virus that infect people inn childhood with no symptoms but may cause mononucleosis-like illness (sore throat, swollen glands, fevers) in adults. Congenital infections(fetus) can also lead to permanent brain damage. In AIDS patients CMV infect retinas of the eyes causing blindness & also adrenal glands leading to hormonal imbalance.
CMV can cause
pneumonia, fevers, rash & gastroenteritis in AIDS patients. CMV pneumonia in patients with PCP is fatal (b) Varicella (shingles) - Painful rash condition that occurs on human trunk. Latent varicella zoster (that causes chicken pox in childhood) is reactivated when the I.S. is compromised.
Antiviral drugs e.g.
acyclovir is sometimes used to control shingles
4. Example of Protozoan infections:
(a) Cryptosporidium gastroenteritis - It is caused by protozoan called cryptosporidium.
It infect lining of the intestinal tract & causes
diarrhea (gastroenteritis). In normal/ healthy people diarrhea lasts a few days but in AIDS patients it is prolonged & severe.
That
is about 20-50 watery stools per day accompanied by abdominal cramps & weight loss (b) Toxoplasmosis - It is caused by Toxoplasma gondii that causes asymptomatic infections in healthy adults.
In AIDS patients it
causes brain infections with symptoms similar to brain tumors (e.g. convulsions, dementias).
5. Examples of Cancers:
(a) Kaposi's sarcoma (KS) - Are tumors of blood vessels.
In non -
AIDS patients KS is seen in older men of Jewish ancestry. Initially few tumors appear as pink, purple or brown skin lesions located on arms or legs. Eventually they spread & become widely distributed in most linings of the body.
They are di cult to control if they
spread to the lungs. Chemotherapy can eradicate them.
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(b) Lymphomas - Cancers derived from B cells of immune system are the common type of lymphomas in AIDS patients.
Epstein-Barr
virus causes mononucleosis but it can also transform normal B cell into cancer cell. Unusual lymphoma that spread to the brain also occur in AIDS patients. (c) Cervical cancers - Its common in female AIDS patients. Infections with certain strains of Human Papilloma Virus (HPV) that cause warts in the genital tract is an underlying cause of cervical cancer. Cancer caused or induced by HPV develops faster when immune system is compromised in AIDS patients. (d) Hairy leukoplakia - Abnormal condition of the mouth in which white plaques appear on the surface of the tongue. This is due to abnormal growth of papillae cells of the tongue. They can't be scrapped o. They resemble cancer cells.
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Exercise 6.
Revision Questions
The progressions of HIV to AIDs involve dierent stages of clinical developments. Discuss
Example
.
Factors that lead to faster development of HIV infection to full
- blown AIDS
Solution :
Age - Persons who get infected after the age of 35years move faster
from HIV infection to full blown AIDS than those who get infected in their mid 20s. Children who get infected at birth die faster simply because their immune system is not well developed at their tender age. Type of HIV contracted There are two well known types: HIV1 and HIV2. HIV1 is harsher on people hence kills faster than HIV2. Mode of transmission - HIV got through blood transfusion kills faster than one got through sexual contact. This is because the amount of virus channeled into the bloodstream is in large quantity. Ill - health & other types of infections - People who are already sick & then get infected move faster than those infected when healthy - Tropical diseases such as malaria, typhoid & intestinal worms makes patients to develop AIDS faster Nutritional status - Those infected & are not eating enough of will balanced foods are more likely to develop AIDS faster. Lifestyle - People who expose themselves to re-infection with other strains of HIV or STIs/STDs and other illnesses move faster from HIV to AIDS. Opportunistic infections - If they are not competently treated, then the HIV+ person develops AIDS faster.
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References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 6 Transmission and diagnosis of HIV Learning outcomes Upon completing this topic, you should be able to understand:
Various methods used in diagnosis of HIV
The modes of HIV transmission
Pregnancy and HIV/AIDS
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6.1. Transmission of HIV
HIV is present in semen, vaginal/ cervical secretions & body uids. It may be present in tears, urine, csf, breast milk &infected discharges, saliva.
HIV is spread when an infected individual come into contact
with infected body uids or cells. How HIV is NOT transmitted.
There is no evidence to show that HIV can be transmitted by:
casual social contact e.g. shaking hands, hugging
sneezing or coughing
shared facilities & equipment e.g. toilets, swimming pools
non wet kissing
sharing food & utensils
insect bites e.g. mosquitoes - HIV only lives for a short time and does not reproduce in an insect
Injecting with sterile needles
Protected sex - If an unbroken latex condom is used, there is no risk of HIV transmission. There are myths saying that 'some very small viruses can pass through latex' - this is not true.
6.1.1. Modes of HIV Transmission 1.
Sexual contact - Any unprotected (no condom) penetrative sex whether vaginal, anal or oral can transmit HIV from infected individual to uninfected sexual partner.
(a) Heterosexual contact (man &woman) a/c 70%-80% of all HIV transmission. (b) Homosexual contact a/c 5-10% (c) Oral sex is low risk but oral ulcers, bleeding gums, genital sores & presence of STIs (gonorrhea, syphilis & genital ulcers) do increase the risk of hiv transmission
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(d) Rape, & sodomy victims could get infected if the attacker is HIV+. The victims should seek prompt medical attn because early treatment with ARVs can greatly reduce chances of HIV infection. They will also require specialized counseling & psychological /psychiatric care Factors that in uence transmission through sexual contact (e) The risk of HIV transmission through sexual contact is in uenced by a number of factors: i. level of virus in the body ii. number of sexual partners iii. sex male/female iv. age v. STDs/STIs vi. Condom use 2.
Intravenous Drug Use/ Contaminated Piercing Instruments
-
I.V. drug use is the administration of drugs of addiction e.g heroin into the blood stream by injecting into the veins. Most drug users tend to shoot in groups & often share needles. It therefore becomes very easy for transmission /infection to occur from one infected group member to another. It's a signi cant modes in the developed countries accounting for 5-10% of HIV infections. Procedures such as ear piercing & circumcisions when done with poorly cleaned & unsterile instruments can lead to HIV transmission. 3.
Occupational exposure/ Infection in the health-care setting
-
Occupational exposure is the accidental exposure of healthcare workers (e.g doctors &nurses) to body uids from an infected patient in their care. This is most frequently due to needle pricks or cuts with surgical instruments. Infection can also occur due to contact with infected blood, laboratory samples especially through broken skin. 4.
Mother - to - child transmission (MTCT)
- Also called Vertical
/ perinatal transmission & it accounts for 13-40% HIV infections. It's possible for HIV to be transmitted from HIV+ mothers to unborn child. This occurs in 3 ways:
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(a) During pregnancy- The virus crosses from mother's blood to child through the placenta. Although there's no exchange of blood between mother & child, researchers believe that the foetus can get HIV through the placenta i.e through diusion.
It accounts for
about 35% HIV infections (b) During birth Through exposure to mother's blood & other secretions. It accounts for 65% HIV infections (c) After birth- through breast feeding. Breast milk contains minimal quantities of HIV. It accounts for 15% HIV infections.
6.1.2. Factors that increase chances of MTCT/ Determinants
high level of HIV in mother's blood & other body uids (maternal viral load)
duration of exposure to maternal secretions during delivery
inadequate nutrition
pre-term delivery- premature babies are more prone to infection because the immune mechanism is still very weak/ immature
Maternal immune response- maternal CD4 cell count
prolonged membrane rupture-increased risk if more than 4hours
obstetrical procedures- e.g. vacuum assisted delivery
unprotected sexual intercourse
presence & amount of virus in the genital tract
Placenta barrier- breaches in barrier leads to mixing of maternal and foetal cells
Presence and amount of HIV in genital tracts
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6.1.3. Prevention of MTCT (PMTCT)
Prevent HIV infection in women i.e. encouraging teenage girls to delay sexual relationships & discordant couples to use of condoms.
Reduce the number of HIV exposed pregnancies i.e.
Women who are
HIV infected can use family planning methods to prevent pregnancies.
ART- to infected pregnant women.e.g. AZT (zidovudine/ azidothymidineNov `94) is taken in the last week of pregnancy and nevirapine is given at the onset of labour & to the HIV exposed babies within 3 days after birth
Preventing malaria - A woman who is infected with both HIV and malaria has an increased chance of passing HIV to her baby.
Anti-
malarial drug treatment during pregnancy is therefore an important part of preventing MTCT
Reducing trauma and shortening exposure of the baby to the virus during labour and delivery i.e. Modi ed obstetrical practices which include
make sure that the mother gives birth within 4 hours after membrane ruptures (water breaks),
avoid routine episiotomy,
avoid prolonged labour,
minimum use of vacuum or forceps delivery, and
Electing to use caesarian section.
Appropriate choice of feeding infants i.e. breastfeeding exclusively without any supplements followed by abrupt but timely weaning or replacement feeding from birth without any breast milk.
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6.2. Diagnosis of HIV and AIDs A number of tests are used to con rm the presence of antibody to HIV and to assist in diagnosing HIV infection.
6.2.1. The Enzyme-Linked Immunosorbent Assay (ELISA)
The test identi es antibodies directed speci cally against HIV. The ELISA test does not establish a diagnosis of AIDS. Rather, it indicates that the person has been exposed to or infected with HIV. People whose blood contains antibodies for HIV are said to be seropositive. HIV antibodies do not reach detectable levels in the blood for one to three months. This period is known as sero conversion during which antibody production to viral proteins take place. Window period is the time during which antibody detection using Elisa is negative.
In some cases it may take
even 6 months for the antibody levels to get high enough for detection.
6.2.2. The Western blot assay
It is another test that can identify HIV antigens and is used to con rm seropositivity as identi ed by the ELISA. This is a method that detects very low antigen levels such that one may test HIV negative by ELISA but test positive through western blot. Babies born of HIV mother have antibodies to HIV that were passed on during pregnancy through the placenta.
However these antibodies diminish with time such that by
15 months the child may test negative. Use of Western, blot con rms presence of HIV antigen and this rules out whether babies are positive because of HIV itself or because of maternal antibodies.
6.2.3. PCR
It is also used to detect HIV in high-risk seronegative people before the development of antibodies, to con rm a positive ELISA, to screen neonates, and to determine the exact strain of virus that is present.
6.2.4. CD4+Cell count
Once a patient is diagnosed positive the extent of damage to the immune system is determined by CD4+ cell count (T-helper cell count).
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The number of CD4 cells present is a direct indicator of the immune system's ability to ght o opportunistic infections. The test to measure CD4 cells requires a sample of blood to be taken and measurement is made of the number of CD4 cells in a cubic milliliter of blood and will give a picture of the health of the immune system-whether it is improving or declining. The CD4 count of a person who is not infected with HIV may lie anywhere between 500 and 1200.A drop in an HIV positive persons CD4 count usually occurs over a number of years. A CD4 count between 500 and 200 indicate that some damage to the immune system has occurred and a count below 350 or rapid decline is an indication that one should consider anti-HIV treatment.
6.2.5. Measuring viral load
Measuring viral load is essential to determine how active the viral replication is if one is taking anti-HIV medication, then it is also a direct indicator of how successful it is in suppressing viral replication.
The
viral load test requires the collection of a blood sample and estimates the number of HIV particles in the sample by looking for HIV genes. The level of viral load is generally seen as a good indicator of whether to start ant-HIV treatment. An undetectable viral load is an indication that both the risk of developing AIDS and the risk of developing drug resistance has been reduced. A high viral load is an indication of high levels of HIV in body uids while undetectable viral load indicates a reduction in levels of HIV in these uids but the risk of transmitting the virus is still present
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6.3. STIs, STDs, FGM and HIV/AIDS STDs are diseases that are transmittable from an infected person to another through sexual intercourse. STIs is a term applied to infections that are transmitted primarily through sexual contact be it vaginal, oral, or anal intercourse. They don't necessarily involve sexual activity but the organisms that cause STIs enters mostly through the soft & thin skin that cover the inner surfaces i.e.
mucus membrane of the vagina, urethra, anus & mouth.
However, in
some instances exposure to sores or other types of skin to skin contact may be insu cient to transmit the infection.
6.3.1. Common examples of STIs/ STDs
Syphilis
Gonorrhea
Candidacies
Hepatitis B & C.
Chancroids ( genital sores)
Genital herpes (Herpes Simplex V)
Genital warts( Human Papilloma V)
Bacterial vaginosis.
Trichomoniasis
6.3.2. Relationship between HIV & STDs/STIs STIs/STDs increase the risk of HIV infection by mobilizing a high population of T cells to ght the STI/STD. Since the T cells are the target cells for attack by HIV, such a large population will inevitably provide breeding ground for HIV. STDs/STIs also increase the risk of acquiring or transmitting the virus. Both are transmitted through sexual contact & to unborn baby during pregnancy or at birth.
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6.3.3. Dangers/ risks of STDs/STIs
Increased risks of getting infected with HIV or the risk of infecting others
High incidences of infertility e.g. pelvic in ammatory disease if untreated result in infertility or tubal pregnancies.
Future problems with pregnancies & child birth
Mental disorders & deaths especially in syphilis Treatment of STDs/STIs
STDs/STIs require medical examination & medical treatment. Any person who has contracted STD/STI & is receiving treatment should also:
Receive counseling from a quali ed health worker on how to avoid future infections
Take all medicines prescribed exactly according to all the instructions
Inform all sexual partners of the need to get examined & treated
Abstain from further risky sexual behaviors
Use condoms for protection
6.3.4. Why teenagers don't seek treatment
Lack of con dentiality
Hostility of service providers
Stigma attached to STIs/STDs
Financial constraints for the youth who are unemployed e.g. anti-fungal drugs( di unisal pessaries) - clears most infection and it costs Ksh.1500 per tablet
Ignorance of availability of service providers
NB: these concerns could be addressed through training service providers to be youth friendly & availing information, education & communication materials to the youth
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6.3.5. FGM (Female Genital Mutilation) It's a destructive invasive procedure usually performed on girls before puberty. It involves surgically removal of part or the whole clitoris using razor blades, knives, and scissors.
Since the victims are young they are unable to give
their informed consent.
FGM is forced on approximately 6000girls per day
world wide. Because of poverty & lack of medical facilities the procedure is frequently done under less hygienic conditions & often without anaesthesia. A person who is not medically trained usually circumcises about 20 girls of same age group.
• Types of FGM 1.
Sunna
- its most widely practiced in sub-Saharan and middle east. It
involves removal of the tip of the clitoris. 2.
Intermediate-it's
where the whole clitoris and adjacent parts such as
labia major and labia minor are removed. 3.
Pharoic - it's the total removal of the clitoris, labia minor, labia major and where the two sides of the vulva are drawn together and then fastened leaving a small opening for urinating and menstruating. This is especially in Somalia.
• Eects of FGM leads to conditions that favours HIV survival They include;
An abnormal anatomy with anatomical distortion
Partial closure of the vagina
Incomplete healing brought about by infections i.e. acids & organisms from urine
Scar formation which may be excessive
Urinary tract infection f ) In ammation of the genital area
Chronic urinary retention - urine is broken down to urea & uric acid accumulates in joints & causes gout.
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Exercise 7.
Revision Questions
Discuss various methods used in HIV/AIDS diagnosis
Example
.
What is CDC's guidance on ART and preventing the sexual
transmission of HIV?
Solution : Know your HIV status-get tested: Knowing whether or not you have HIV is the rst step toward keeping yourself healthy and avoiding passing infection on to others. Continue to get tested regularly if you engage in ongoing risk behavior. If you are HIV infected, know about ART: See a healthcare provider and nd out if you should be on ART. Even if you do not need ART at rst, keep your appointments for check-ups so that you will be able to start when you do need it.
Current guidelines suggest that ART be started when the CD4
cell count is between 350-500. However, it may be started when CD4 counts are greater than 500, depending upon your situation. For example, pregnant women and people with certain medical conditions should start earlier, at higher CD4 counts.
ART can also be started earlier to help prevent HIV
transmission to partners at risk for infection.
Ask your healthcare provider
about when the time is right for you. If you are on ART, take it correctly and consistently: ART drugs work best when the right doses are taken at the right times. Not taking them properly gives the virus a chance to multiply and sometimes become resistant to the medications. Taking ART as recommended will give you the best chance of staying healthy, and will probably help lessen the chance of infecting others. Whether you are infected or not, know what to do to prevent transmission of HIV: Eective ART and an undetectable viral load will probably decrease the risk of transmission, but ART alone will not prevent all new infections. For additional protection, other prevention methods-abstinence, sex only within a mutually monogamous relationship, and condoms-should be used.
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Revision questions or guidelines 1. What are the advantages of pre-test counseling? 2. Explain the expected reactions that might be encountered by an HIV positive individual. 3. State the advantages of knowing ones HIV status. 4. What are the components of home-based care of HIV/AIDS patients? 5. VCT is a powerful weapon in the ght against HIV/AIDS. Explain the role of VCT centers as a HIV/AIDS management strategy. 6. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 7 Prevention and treatment of Hiv/Aids Learning outcomes Upon completing this topic, you should be able to understand:
Prevention and control of mother to child transmission
HIV Post exposure prevention
Classes of drugs used against HIV
Limitations of antiretroviral therapies
Development of new HIV drugs and vaccine
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7.1. Prevention and control of mother to child transmission There are certain factors that may reduce the risk of transmission from mother to baby. They includes:
Taking anti-HIV therapy during pregnancy and delivery e.g. AZT which reduces the viral load.
An elected caesarean section instead of normal delivery
Not breast feeding where there is access to safe, adequate milk substitutes.
Breast feeding should be avoided because the HIV virus is
present in breast milk. Also it is not uncommon for mothers to experience cracked or bleeding nipples while breastfeeding, therefore increase the risk of viral transmission.
Mothers who are HIV positive should not donate breast milk to breast milk barks, neither should they express milk to be bottle fed to their baby.
7.2. Prevention and control of transmission through blood and other blood products
Screening all donated blood especially for transfusion.
Careful handling of blood and body uids
Avoidance of sharp injuries, needles, knives, clips, sharp objects in hospital working situation
Used needles should be disposed in the right tray.
Never pick up a sharp object without looking
Use of gloves (heavy gloves) when you sense danger
Avoid skin/mucous membrane contaminations.
Equipments should be
thoroughly and properly sterilized. This is because HIV is very sensitive and easily destroyed by boiling at least 5 minutes and is susceptible to a wide range of disinfectants
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7.3. HIV Post exposure prevention Studies show that under certain circumstances, administering antiretroviral drugs within 24 hours (preferably within one to two hours) after exposure to HIV can protect a person from becoming infected with the virus. Although the eectiveness of post exposure antiretroviral therapy following sexual exposure to HIV remains uncertain, the Center for Disease Control, USA, recommends that health-care personnel exposed to HIV infection from a needle stick or other accident take antiretroviral drugs.
7.3.1. Ways in which HIV cannot be transmitted
Kissing (except in cases of deep kissing where copious amount of saliva is exchanged), touching, hugging or shaking hands
Sharing crockery and cutlery
Coughing or sneezing
Contact with toilet seats
Insect or animal bites e.g. mosquitoes, bedbugs.
Swimming pools
Eating food prepared by someone with HIV.
7.4. Treatment of HIV
The four main classes of drugs used against HIV are:
Nucleoside Analogue Reverse Transcriptase Inhibitors
Non-nucleoside Analogue Reverse Transcriptase Inhibitors
Protease Inhibitors
Entry Inhibitors
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7.4.1. Nucleoside analogues reverse transcriptase inhibitors These impede the action of reverse transcriptase, the HIV enzyme that converts the virus's genetic material into DNA. During this conversion process, these drugs incorporate themselves into the structure of the viral DNA, rendering the DNA useless and preventing it from instructing the infected cell to make additional HIV. Examples include AZT, didanosine (sold under the trade name Videx), zalcitabine (HIVID), stavudine (Zerit), lamivudine (Epivir), and abacavir (Ziagen)
7.4.2. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) They use a dierent mechanism to block reverse transcriptase. These drugs bind directly to reverse transcriptase, preventing the enzyme from converting RNA to DNA. Three NNRTIs are available: nevirapine (Viramune), delavirdine (Rescriptor), and efavirenz (Sustiva).
7.4.3. Protease inhibitors These cripple protease, the enzyme vital to the formation of new HIV. When these drugs block protease, defective HIV forms that is unable to infect new cells. These drugs are taken orally and act against HIV directly. As the chemicals produced by the new DNA attempts to make copies of HIV, the protease inhibitors act against them and prevent them from working correctly.
New
particles of HIV produced in the presence of protease inhibitors are immature and non-infections.
Examples are saquinavir (Invirase), ritonavir (Norvir),
indinavir (Crixivan), nel navir (Viracept), and amprenavir (Agenerase).
7.4.4. Entry inhibitors They are known as entry inhibitors because the rst stage of the process, whereby HIV enters a CD4 cell is the binding or fusion of the HI virus with a particular part of outer wall of the CD4. The entry inhibitor is a drug speci cally designed to t between the HIV particle and the point of the CD4 cell to which it needs to bind to gain entry and therefore prevent this happening.This is the newest class of anti-HIV drug. The best known drug in this class is T-20, which is taken by injection into a muscular part of the body.
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7.4.5. Limitations of antiretroviral therapies
ARVs have a number of limitations. They include drug resistance, side eect and costs of treatment:
• Drug resistance
Clinical studies of treatment with antiretroviral drugs have showed that their bene ts are short-lived when a single drug is used alone.
This
short-term eectiveness results when HIV mutates, or changes its genetic structure, becoming resistant to the drug. The genetic material in HIV provides instructions for the manufacture of critical enzymes needed to replicate the virus. Scientists design current antiretroviral drugs to impede the activity of these enzymes. The structure of the virus's enzymes changes if the virus mutates. Drugs no longer work against the enzymes, making the drugs ineective against viral infection, and resistance sets.
Genes mutate during the course of viral replication, so the best way to prevent mutation is to halt replication.
Studies have shown that the
most eective treatment to halt HIV replication employs a combination of three drugs taken together, for instance, a combination of two Nucleoside Analogues with a Protease Inhibitor. This regimen is called triple therapy (also known as Highly Active Antiretroviral Therapy - HAART) and it maximizes drug potency while reducing the chance for drug resistance. The combination of three drugs is often referred to as an AIDS cocktail.
In HIV-infected patients who have undergone triple therapy,
the viral loads reduced signi cantly, sometimes to undetectable levels.
Despite phenomenal success, triple therapy has some drawbacks. This multidrug therapy is quite complicated, requiring patients to take anywhere from 5 to 20 pills a day on a speci c schedule. Some drugs must be taken with food, while others cannot be taken at the same time as certain other pills.
Even the most organized people nd it di cult to
take pills correctly. Yet, just one or two lapses in treatment may cause the virus to develop resistance to the drug regimen
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• Drug side eects
Many people also nd it di cult to deal with the unpleasant side eects produced by antiretroviral drugs. Common side eects include nausea, diarrhea, headache, fatigue, abdominal pain, kidney stones, anemia, and tingling or numbness in the hands and feet. Some patients may develop diabetes mellitus, while other patients develop collections of fat deposits in the abdomen or back, causing a noticeable change in body con guration. Some antiretroviral drugs produce an increase in blood fat levels, placing a patient at risk for heart attack or stroke. Some patients suer more misery from the drug treatment than they do from the illnesses produced by HIV infection.
To decrease the toxic eects of drugs and to defer costly therapy, it advisable to delay drug treatment for HIV infection in people showing no symptoms and who have been infected with HIV for more than six months. The new guidelines call for delaying treatment until an infected person's CD4 cells fall below 350 cells per microliter of blood or the HIV viral load exceeds 30,000 per microliter of blood. Evidence suggests that delaying treatment poses no harm to infected people and, in fact, bene ts them by deferring the toxic side eects of the drugs.
• Cost of treatment
The greatest drawback to triple therapy is its high cost, which is well beyond the means of people with low incomes or those with limited health-care facilities. As a result, the most eective therapies currently available remain beyond the reach of the majority of HIV-infected people worldwide.
7.4.6. Development of new HIV drugs and vaccine
Scientists continue to develop more powerful HIV treatments that have fewer side eects and fewer resistance problems. Some drugs under investigation block the HIV enzyme integrase from inserting viral DNA into the infected cell.
Other drugs prevent HIV from binding with a
CD4 cell in the rst place, thereby barring HIV entry into cells.
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Some scientists focus on ways to fortify the immune system. A biological molecule called interleukin-2 shows promise in boosting the immune system's arsenal of infection- ghting cells. Interleukin-2 stimulates the production of CD4 cells. If enough CD4 cells can be created, they may trigger other immune cell responses that can overpower HIV infection.
In other research, doctors hope to bolster the immune system with a vaccine. Most vaccines available today, including those that prevent measles or poliomyelitis, work by helping the body to create antibodies.
Such
vaccines mark speci c infectious agents, such as the measles and polio viruses, for destruction. But many experts believe that an eective HIV vaccine will need to do more than just stimulate anti-HIV antibodies. Studies are underway to develop vaccines that also elevate the production of T cells in the immune system.
Scientists hope that this dual
approach will prime the immune system to attack HIV as soon as it appears in the body, perhaps containing the virus before it spreads through the body in a way that natural immune defenses cannot.
7.4.7. Challenges in Developing AIDS Vaccines
HIV continually mutates and recombines. This may mean that a vaccine would need to protect the person against many strains of the virus. Vaccines against other viruses have only had to protect the person against one or a limited number of strains.
HIV infects helper T cells, the immune cells that orchestrate the immune response. It is very di cult to design a vaccine that, to be eective, needs to activate the very cells the virus infects. HIV can be transmitted as both free virus and in infected cells.
This may mean that both arms
of the immune system (humoral and cellular mediated) may need to be stimulated.
Researchers do not know what constitutes an eective immune response to HIV. It might be antibodies, activated immune cells, perhaps a third immune response, or a combination of immune responses. Researchers lack an ideal animal model for AIDS vaccine testing
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7.4.8. Treatment of opportunistic infections
In addition to antiretroviral therapy to combat HIV infection, eective drug treatments are available to ght many of the medical complications that result from HIV infection. Doctors try to prevent infections before they begin to avoid taxing a patient's weakened immune system unnecessarily.
A doctor instructs an HIV-infected person on ways to avoid
exposure to infectious agents that produce opportunistic infections common in people with a weakened immune system. Doctors usually prescribe more than one drug to forestall infections. For example, for those who have a history of pneumocystic pneumonia and a CD4 cell count of less than 200 cells per microliter, doctors may prescribe the antibiotics sulfamethoxazole and trimethoprim to prevent further bouts of pneumonia. Patients suering from recurring thrush may be given the antifungal drug uconazole for prolonged periods. For people with CD4 cell counts of less than 100 cells per microliter, doctors may prescribe clarithromycin or azithromycin to prevent Mycobacterium avium infections.
• Support mechanisms
A person diagnosed with HIV infection faces many challenges, including choosing the best course of treatment, paying for health care, and providing for the needs of children in the family while ill. In addition to these practical considerations, people with HIV infection must cope with the emotional toll associated with the diagnosis of a potentially fatal illness. The social stigma that continues to surround a diagnosis of AIDS because of the disease's prevalence among gay men or drug users causes many people to avoid telling family or friends about their illness. People with AIDS often feel incredibly lonely as they try to cope with a devastating illness on their own. Loneliness, anxiety, fear, anger, and other emotions often require as much attention as the medical illnesses common to HIV infection.
Counseling centers and churches provide individual or group counseling to help people with HIV infection or AIDS share their feelings, problems, and coping mechanisms with others. Family counseling can address the emotions of other family members who are disturbed by the diagnosis
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of HIV infection in another family member. Grief counseling also helps people who have lost friends or family members to AIDS.
Voluntary Counselling and Testing Services (VCT) Counselling is advice or guidance, especially as provided by a professional in a given eld. Counselors are people who are trained to help others to understand their problems, identify and develop solutions, and make their own decisions about what to do.
Counselling involves being with them, listening to
them talk about their problems and fears, helping them to increase their own self-esteem, and when necessary giving correct and useful information based on what they need to know at that point in time. Voluntary counselling and testing (VCT) is an important strategy for management of HIV/AIDS. It is a powerful weapon in the ght against HIV/AIDS since it is associated with behaviour change that reduces HIV transmission and serves as a point of entry into care for those testing.
The national VCT programme uses four models of service delivery:
integrated,
stand-alone,
community-based
and mobile.
In integrated sites, a VCT centre is usually located within the grounds of health facilities such as hospitals, health centres or dispensaries. Standalone sites are usually not associated with any existing medical institution and usually have sta fully devoted to VCT. They are largely operated by non-governmental agencies and are usually located in densely populated urban areas.
In the community-based sites, VCT is either
integrated into other social services or implemented as the sole activity of a local community-based organization (CBO) or a faith-based organization (FBO). In the mobile sites VCT is provided as an outreach to remote or hard-to-reach communities where other models of VCT are either not feasible or unavailable.
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There may be any number of reasons why a person may want to undergo a test to discover whether they are HIV positive.
Medical reasons for testing
*
Pregnancy
*
STDs
*
Legal insurance,
*
visas, s
*
cholarships
Voluntary testing
*
Desire to know HIV status
*
For those expecting to marry/for future partnership.
*
Experiencing symptoms indicative of HIV.
7.4.9. Steps involved in HIV testing in VCT
• Pretest counseling HIV counseling is an eective public health intervention because it promotes the health of HIV infected persons and plays a role in reducing HIV transmission. Aims of a pretest counseling Ensure you have a full understanding of the implications of the test and are able to make an informed decision whether to test. Ensure informed consent (to carry out the test) is gained from you. Give you the opportunity to discuss routes of HIV transmission Discuss the implications and support needs that may follow either appositive or negative test result. Consider ways to reduce transmission or contraction of the virus in the future. Encourage you to consider and evaluate the impact the result may have on you emotionally, physically and in relation to your lifestyle. Helps to identify risk factors and symptoms that may indicate that the patient is HIV infected. During the pretest counseling the person thinks of someone to share the results with. To reduce the internalized stigma by providing information about HIV in a neutral environment.
• Advantages of testing 1. Ability to seek medical intervention when one tests positive and this prevent complications of AIDS.
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2. To prevent transmission to others 3. To make healthy life style changes -eat well, exercise. 4. Important also to know cause for various symptoms.
• Disadvantages 1. Increased fear of illness and death 2. Fears related to family relations/parenting 3. Guilt of past relationships and sexual behaviour 4. Stigma associated with HIV/AIDS The patient should be helped to understand the antibody test. Body produces antibodies to HIV that are found in the blood. Positive test mean the person is HIV infected. There is a period of 3-6 months during which antibodies may not show up in the blood and test will reveal the person to be negative. This is the window period. Tests giving negative results should be repeated again after 3 and 6 months respectively.
• Post test counseling If the person test positive:
Explain to them that there is chance of not developing full blown AIDS by medical intervention -ARVs, antibiotics and antifungal, nutrition and reducing stress, and change of lifestyle through positive living.
If results are negative:
Clarify that the test did not yield positive results does not means that the person does not have HIV or has not developed HIV.
Let the person know that there is need to repeat test after 3 months however don't forget to congratulate the person.
Discusses methods to reduce risk of transmission and avoiding risky behaviours.
Discuss the current risk situations of the patient and help to develop strategies to increase prevention of transmission.
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• Role of VCT centers 1. VCT has taken a central role in enlightening and guidance of HIV/AIDS disease. 2. Contribute immensely in the control of HIV/AIDS 3. Involve testing and availing the results to people in minutes. 4. Before testing the people are prepared rst for both positive and negative results before allowed to know their status. Importance of knowing one's HIV status includes:
(a) Preventing the uninfected person from contracting the disease (b) Enhancing abstinence for the infected helps in controlling the disease through self awareness and putting up ways on how to abstain or get involved in safe sex
5. Counseling also helps in ensuring reduced spread of the virus by those people who have been infected but had not shown symptoms. 6. Counseling infected people, majority of who have lost hope, helps in ensuring positive living. 7. Help to reduce the revenge attitude for those innocently infected and may opt to die with many or commit suicide. 8. Counseling enables the public who includes the relatives of the infected to stop stigmatizating those infected to be able to live normal lives knowing that someone cares for them. 9. Testing also helps the government to keep statistics on the prevalence of the disease hence policy development or strategic planning.
• General reactions to testing HIV positive Each of these feelings or reactions is part of a normal response to a situation of great stress.
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A person might move from one response to the next in a progression leading nally to acceptance of their situation, or more commonly their feelings will keep changing. One day they might feel rejected and lonely - the next day hopeful and energetic. One day depressed, another day angry.
Shock - No matter how much someone prepares, it is a shock to learn that one has HIV infection or AIDS. A person might feel confused and not know what to do.
It is good for people to be with someone they
trust at this time.
Denial - At rst they might not be able to believe that they really have HIV or AIDS They might think 'The doctor must be wrong' or "It can't be true - I feel so strong". Not wanting to believe is a strong force that people may use subconsciously to protect themselves from the threat posed by AIDS.
Anger - People might become very angry when they learn that they have HIV or AIDS This is a common feeling and can come when they blame themselves or the person they think gave them HIV. Some may even blame God. Talking to someone can help a person overcome feeling of anger and help them accept their situation.
Bargaining - A person with AIDS might try to bargain, thinking that God will cure me if I stop having sex or the ancestors will make me better if I slaughter a goat or I will be good and AIDS will go away. People with HIV or AIDS need to be helped to get through the feeling of bargaining.
Fear - People with HIV or AIDS fear many things, for example:
Pain of losing their job
Other people knowing that they are infected
Rejection
Leaving their children
Death.
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Loneliness - A person with AIDS might often feel lonely.
This feeling
may come and go for a long time and depends on the support given by family and friends. Anyone who has AIDS must be helped to remember that they are not alone; that they are surrounded by family, friends and a community that cares about them. Many other people have HIV or AIDS.
Self-consciousness - When a person has HIV or AIDS they might think everyone is looking at them or talking about them.
This may make
them want to hide. Sometimes a person with AIDS may feel unworthy of friendship.
Depression - If a person nds out that they have HIV or AIDS they may feel there is no good reason for living. They may feel useless, and want to stay at home, not eat, and not talk to anyone. Depression can make someone weak both in mind and body.
Acceptance - After some time, a person with HIV or AIDS will usually begin to accept their situation. This will help the person to feel better. Such a person will feel more peaceful in their mind, and will begin to think about the best ways to live.
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Revision Questions Example
.
Prevention involves tackling the most important modes of trans-
mission. Discuss brie y how to prevent sexual transmission.
Solution :
Taking anti-HIV therapy during pregnancy and delivery e.g. AZT
which reduces the viral load. HIV positive mothers to choose an elected caesarean section instead of normal delivery. Not breast feeding where there is access to safe, adequate milk substitutes.
Breast feeding should be avoided
because the HIV virus is present in breast milk. Also it is not uncommon for mothers to experience cracked or bleeding nipples while breastfeeding, therefore increase the risk of viral transmission.
Mothers w ho are HIV positive
should not donate breast milk to breast milk barks, neither should they express milk to be bottle fed to their baby.
Exercise 8.
Discuss the role of Voluntary Counseling and Testing (VCT)
centers in HIV/AIDs management
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Revision questions or guidelines 1. Discuss HIV/AIDS prevention and control strategies 2. Explain the factors that account for the continued rise in women infected with HIV compared to men. 3. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 8 Concept of positive living Learning outcomes Upon completing this topic, you should be able to understand the following:
Components of home based care
Relationship between good nutrition and management of HIV
Reducing the risk of transmission during pregnancy
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8.1. Introduction The rst stage of positive living is accepting wholly HIV is part of you and this cannot be changed and start taking good care of yourself: 1. Breath - When you get overwhelmed, take three deep breaths. Breathing better is one of the most important things you can do to maintain your health. It improves everything from chronic health problems, stress related disorders to our sporting performance. Whether you want to boost your workout, ease stress or improve your health, learning to breathe properly can enhance your quality of life.
Look for fresh air, like the
around lakes, forests, near rivers and water falls, at the seashore and after a rainstorm that is know to contain abundant negatively charged ions.. This kind of air is refreshing and gives people a lift. House plants also do more than enhance the appearance of the home and o ces. They enrich the air with oxygen and absorb carbon dioxide. Some even remove toxic pollutant from the air we breathe (Ang'awa 2005).
Bad air and
poor breathing habits interfere with breathing, reducing the oxygen delivered to the blood and impairing performance and mood and promotes negative emotions like depression, irritability, headaches and feelings of fatigue and exhaustion because the body is robbed of this vital element (Ang'awa 2005) 2. Refuse to be a victim - Focus on what you can do. Focus on living with HIV and not dying of AIDS. Live one day at a time. Seek support not pity 3. Educate yourself about HIV - Attend HIV/AIDS seminars, workshops or any education forum. 4. Physical exercise - Necessary for all parts of the body 5. Reduces stress
(a) Keep busy (b) Do not concentrate on self. (c) No self pity, concentrate on development
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(d) Do not overwork.
6. Express yourself, ask for support -
(a) Talk to your friends (b) Share feelings with your partner, friends and family (c) Professional counselor, therapists and clergy can oer support
7. Embrace your own spirituality
(a) Faith based organizations have ministers who support HIV positive people (b) If you feel angry with God, acknowledge it. HIV is a virus not a punishment.
8. Think and act positively 9. Seek out people who are honest, trustworthy and supportive 10. Cry when you need to let it out, as it creates room for positive feelings 11. Accept responsibility - Pledge that HIV stops with you. liberately seek to infect others.
Do not de-
Use condoms to pr others and avoid
re-infection. 12. Talk to other people with HIV - group therapy works.
Join support
groups 13. Healthy and diet - eat well balanced diet with lots of proteins and vitamins Avoid food poisoning as much as possible Avoid alcohol, drug and substance abuse 14. Attend to opportunistic infections immediately 15. Have hope about many things. For example:
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It is important to have hope.
Hope lifts spirits and gives strength to face
each situation. Hope can help each person to ght HIV and AIDS - to live positively and to live longer. Remember, even if a person has hope today, it is possible to feel angry or depressed tomorrow. This is normal. Even people without HIV or AIDS go up and down emotionally every day. The important thing is to try to instill the feelings of hope again and again.
8.2. Home Based Care Home based care means - any form of concern given to sick people in their own dwellings. It can mean the things people might do to take care of themselves or the care given to them by the family or it can be extended from the hospital or health facility to the patient's home through family participation and community support (Gilks et al. 1998., MOH 2002c). Care includes physical, psychosocial and spiritual activities. The term family here refers to the person (or people) with the main responsibility for caring for a person with AIDS in the home.
In fact, the person providing such care may be a blood relative,
a relative by marriage (a spouse for example), a friend, a neighbour or some other person. The overall goal of home based care is - to ensure a high standard of human, holistic care that meets the needs of People living with HIV/AIDS (PLWA's). PLWA's have basic, physical, economic and psychosocial needs. These can be met at the familiar home environment and may lead to an improvement of the quality of life for PLWA's. Home based care establishes an important link between health professionals and the caregivers at home. HIV /AIDS aect all aspects of social and economic life in Kenya.
The
health sector is aected by an increased burden of caring for those infected. It is responsible for delivering eective treatment of opportunistic infections, providing compassionate care and implementing many prevention programs such as STD control, condom promotion and distribution and health education and provision of Anti retroviral drugs (ARVs). It is estimated that 51 % of the bed occupancy in public hospitals in Kenya is by AIDS patients1.
The national health systems cannot cope with the
accelerating demand as increasing number of people with full blown AIDS develop opportunistic infections. The nancial investments required to treat
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AIDS are beyond national budgets. Not only is the cost of care beyond health care systems, but it is beyond the reach for the individual and the family. Family, friends and the community must ll the "care gap" at large. This group of care givers has the capacity and resources to do more than the national health care systems: they take care of the sick, replace their labor/income, care for their dependants, and help defray costs associated with the illness, provide palliative care of PLWA's and quality life in death.
The use of caregiver is
instrumental in reducing the stigma associated with HIV/AIDS. Thus, the concept of home based care.
8.2.1. Rationale for Home Based care
The people living with HIV/AIDS are discharged from hospital where trained professionals are and sent home where they are usually cared for by untrained relatives
PLWA's need continued quality care to prolong lives and reduce suering
There are limitations on hospital care, including limited resources that aect the care that can be given to PLWA's. Continued hospitalization of PLWA's may lead to depletion of family and community savings and investments.
8.2.2. Advantages of organized home based care
It aects the socioeconomic, psychosocial and medical well being of the patient, the family, the community and the health care system.
It provides comfort of a familiar environment to the PLWA,
It is less expensive for families
It helps counteract the myths and mistaken beliefs about HIV/AIDS
It encourages people to take steps to prevent infection.
It encourages community participation in the care of PLWA's and thus maintains community cohesiveness in responding to community members' needs.
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It eases the demand on the national health system by reducing crowding in hospitals, thus better care is given to those who really need to be in hospital.
8.2.3. Components of home based care
Clinical management - which includes early diagnosis, rational treatment and planning for follow up care of HIV related illness
Nursing care - which includes care to promote and maintain good health, hygiene and nutrition
Counseling and psycho social care - which includes reducing stress and anxiety, promoting positive living, and helping individuals to make informed decisions on HIV testing, plan for the future and behavior change
Social support - which includes information and referral to support groups, welfare services and legal advice for individuals and families and where possible provision of material assistance
8.2.4. Aspects of nutrition in comprehensive care of HIV/AIDS patients Nutrition implies the process of absorbing nutrients from food and processing them in the body in order to keep healthy or to grow. Adequate food security in the household is requisite for optimum nutrition, health and survival (FAO 2002). But HIV/AIDS reduces the household's ability to produce and buy food by taking away the adult labour that would otherwise be engaged in agricultural production or in earning an income. increases health expenditure.
At the same time, HIV disease
The capacity of an aected household to ob-
tain an adequate amount and variety of food, and to adopt appropriate health and nutritional responses to HIV/AIDS, especially for the already vulnerable ones, is grossly reduced. On the other hand both HIV/AIDS and malnutrition compromise the immune system, resulting in increased susceptibility to severe illnesses, which reduce the quality of life and shorten life expectancy.
Mal-
nutrition due to HIV/AIDS is linked to inadequate food intake, poor uptake of food into the body, and poor use and storage of nutrients. Each of these factors must be considered in providing the most appropriate nutritional care
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for the HIV-positive person. Reduced food intake in persons with HIV may be due to painful sores in the mouth and throat, loss of appetite, or fatigue. The main causes of loss of appetite are infections and depression. Other causes include side eects of medication such as nausea and vomiting, and inadequate access to and availability of appealing foods. Poor absorption of nutrients results when HIV damages the small intestine and alters the healthy bacteria of the digestive system, causing malabsorption of fats and carbohydrates and frequent episodes of diarrhea. Intestinal infections also cause diarrhea, with loss and waste of nutrients. Infections, including HIV itself, lead to increased requirements for energy and protein, ine cient use of nutrients, and loss of nutrients. Energy requirements are likely to increase by 10% to maintain body weight and physical activity in adults and growth in symptomatic children.
• Advantages of good nutrition to PLWA
Good nutrition entails eating a well-balanced diet that contains all the nutrients the body needs for growth and proper functioning. Balanced nutrition helps the body to:
Increase resistance to infection and disease and improve the energy supply.
Boost the immune system and therefore reduce the frequency of episode of morbidity.
Lessen severity of infection, improve the response to treatment for opportunistic infections such as TB, and speed the rate of recovery.
Replace lost micronutrient and provide the body with all essential nutrient required for good health.
Preserve muscle mass, slow or stop the loss of lean tissue, prevent weight loss, and improve body strength and energy.
Delay the rate of progression of HIV to AIDS and the further advance of AIDS itself.
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Keep PLWAs alive and able them to lead an active life; this in turn reduces their dependence, thus allowing them to take care of themselves and to delay early orphan hood of their children.
Studies show that nutrition interventions can positively aect nutrition status (FAO 2002), the immune system and even personal esteem, by maintaining body weight, improving eectiveness of medication and prolonging life. Supplementing micronutrients has been shown to increase life expectancy of subjects with fewer than 200 CD4 cells per millilitre1. A number of micronutrient supplements including vitamin A, zinc and iron have been found to boost the immune system in a person with HIV infection. Multivitamins can reduce the risk of death and improve immune function.
• Principles of nutrition support for PLWA Good nutrition can therefore play an important role in the comprehensive management of HIV/AIDS, as it improves the immune system, boosts energy, and helps recovery from opportunistic infections.
The following basic principles
are being advocated for all programmes of HIV/ AIDS patient management, counselling or education:
Nutritional education and counselling
Water and food safety intervention to prevent diarrhoea
Income-generating activities to enhance food security
Nutritional supplementation
Meal designing and planning using locally available foodstus
To avoid malnutrition and wasting away HIV infected persons should always ensure that they take highly nutritive foods that are well balanced.
High protein diet to build up infected cells and tissues/strengthen them. They include Soya beans, lean meat, milk, beef, eggs.
Carbohydrate foods are required in large quantities to provide the much required energy to strengthen patients who are weak.
They include
Whole meal cereals, cassava, potatoes, and cooked bananas.
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Vitamins and minerals help bodies' in ghting diseases and keep opportunistic infections checked. They also help in a quick recovery and disease management. Vitamins are obtained from fresh vegetables, fruits, fresh juices.
Fluids help in cleaning the immune system, blood puri cation and to improve the appetite (anorexia).
Frequency of food intake should be high to avoid or replace weight loss
8.3. Management of pregnancy in HIV/AIDS The introduction of combination therapy and the impact it has had on improving the health of HIV-positive women, together with the enormous strides made in reducing the risk of transmission from mother to baby has led more HIV positive women contemplating having children. It is advisable to plan a pregnancy well in advance, more so for HIV positive women. Unfortunately, prior planning is not possible for all HIV positive women some will learn of their HIV diagnosis at routine antenatal visit. The women will be promptly referred for additional costs and informed of treatment options to safeguard their own health and the health of their unborn child. Ideally HIV positive women should be seen by specialist midwife and/or obstetrician throughout their pregnancy. This will ensure that both the pregnancy and their HIV can be closely monitored and any additional information, treatment and support made available. HIV positive women should discuss the prospect of pregnancy before hand, ensuring they have the information to ensure the best possible chance of a safe, healthy pregnancy and delivery.
8.3.1. Reducing the risk of transmission during pregnancy This is achieved by antiretroviral therapy. From conception onwards there is a risk of viral transmission from mother to baby. This is increased if;
The mother has high viral load
She is old
She smokes during pregnancy
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She has unprotected sex during pregnancy.
She uses illicit drugs during pregnancy
She has no antiretroviral therapy during pregnancy and delivery
Membrane rapture more than 4 hours before delivery
Delivery is natural and not by caesarean section.
Delivery is prolonged or di cult
Cervical or vaginal infection is present
Membranes are in amed
The mother breastfeeds
Primarily, viral load is the most important factor to in uence the risk of transmission. A high viral load substantially increases the risk of transmission to either a negative partner or unborn child. For this reason, the control of viral load from conception, throughout the pregnancy and during delivery by use of antiretroviral therapy is crucial at speci c pregnancy stages.
• Conception Conceiving a child in relationship where one partner is HIV positive and the other HIV negative presents unique challenges.
If the woman is the HIV
positive partner, arti cial insemination oers the best chance of conception while not risking transmission to her partner. For some couples, assisted conception is not an option and they may choose not to use a condom while trying to conceive a child naturally, this of course increases the risk of HIV transmission to the negative partner.
In these in-
stances it may be wise to restrict unprotected sex to the fertile period of the woman's cycle.
• The pregnancy Optimum health, which for an HIV-positive woman means a low viral load and a healthy CD4 count in addition to good general health, oers the best chance for a healthy pregnancy and baby. There is no evidence to suggest that
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pregnancy accelerates HIV progression. It has been observed that CD4 counts drop in pregnancy, but this is also seen in HIV-negative women. CD4 count usually returns to a pre-pregnancy level soon after delivery. ARVs such as AZT are used to reduce the risk of transmission during pregnancy. AZT is taken orally after the 14th week of pregnancy and intravenously during labour. Administering AZT syrup to newborns for the rst six weeks can further reduce transmission. AZT reduces the risk of mother to child transmission by lowering the mother's viral load during pregnancy and delivery and may act as a post exposure treatment for newborns.
It is the
only antiretroviral that has been thoroughly tested for use in pregnancy. For women who are already taking antiretroviral therapy and other discover they are pregnant after 14 weeks, it is usually advisable that they continue with the establishment therapy as well as AZT.
• Delivery There are con icting opinions regarding whether HIV positive mothers should undergo a vaginal delivery or a planned caesarean section to reduce the risk of transmission to their baby. Until recently all HIV positive mothers were urged to have an elective caesarean. The decision relating to mode of delivery is one that should be reached after all factors have been considered by the mother and her doctor.
• Breastfeeding HIV- positive mothers should not breastfeed their babies as this increases the risk of transmission especially if the mother has a cracked or bleeding nipples and if the baby if teething.
• Testing babies for HIV All babies born to HIV positive mothers will be tested to ascertain whether the virus has been transmitted. Initial testing is undertaken when the child is 48 hours old. Negative children are tested again at day 14 when PCR will identify approximately 90% of infected children. If at 14 days they still test negative, then the test is repeated again at 4-8 weeks and then again at 16-26 weeks of age. If they return two negative results, when they are over 6 month of age, it can be con rmed that the virus has not been transmitted.
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Exercise 9.
Revision Questions
Describe how early detection and treatment of sexually transmitted infections (STIs) are important? Exercise 10.
Explain if one might have been exposed to HIV is there
anything I can do?
Example Solution :
.
Why is HIV testing and counselling important?
More than 90% of people infected with HIV do not know their
HIV status. Voluntary testing and counseling have proved to be an eective public health strategy as they result in reduced risk behaviours and increased condom use. Testing and counselling serve as entry points to HIV/AIDS care and support.
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Revision questions or guidelines 1. Discuss ways employed by the Kenyan government to reduce the impact of HIV/AIDs. 2. Socio-economic and cultural factors greatly contribute to the rapid spread of HIV/AIDS. Discuss. 3. Empowering women in Kenya will contribute towards lowering new cases of infection with HIV. Discuss this statement siting examples. 4. Discuss the role of religion in ght against HIV. 5. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 9 Behavioral patterns and the spread of Hiv /Aids Learning outcomes Upon completing this topic, you should be able to know policies and rights of PLWHAs with relation to:
Individual Behavioral Patterns and the spread of HIV /AIDS
Role of gender in transmission of HIV /AIDS
Drug/Alcohol use and use and the spread of HIV/AIDS
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9.1. Individual Behavioral Patterns and the spread of HIV /AIDS Behaviour can be de ned as all those process by which an organism senses the external world and the internal state of its body and responds to changes which perceives. Many of such process will take place inside the nervous system and may not be directly observable. An organism may respond by involving in a violent activity or incomplete inactivity, but all are equally behaviour. The spread of HIV primarily depends on individual's sexual behaviour patterns how often men and women have sex and who they have sex with. Not everyone's sex life is the same and patterns of sexual behaviour are strongly in uenced by social, cultural and psychological factors over which men and women have little control.
In most societies, men are generally expected to be strong leaders,
to be primary providers of their family's food, shelter and defend themselves, their families and societies from aggressors. Virility-the ability to perform sex is almost an essential component of masculinity in almost every society. Young people are expected to prove their sexual prowess and there is under spread belief that a man's need for sex is beyond control.
For men anything that
appears to interfere with their sex lives such as appeal to abstinence or use of condoms is a threat to their masculinity. Impelled by these attitudes, men on average report more sexual partners than women. The implication of this are that women are likely to contract HIV but less likely to transmit the virus to other sexual partners while men are more likely to contract and transmit the virus. In the long term this means that more women than men will contract HIV. Compounding this situation is the fact that many men do not consider sex as a consensual activity. Sex has to take place when man decides and without a condom if he chooses. Wives are often beaten or ejected from their home. If they refuse to submit to their husbands and many women are at risk outside the home if they refuse to submit to their husbands and many women are at risk outside the home. In such instances, women nd it impossible to protect themselves from infection with HIV or other STI's. In prisons or other single sex environments some men rape other men either as a substitute for sex with a woman or to establish power over their victims. In other situations, however, sex between men may be an expression of mutual desire or the result of ones desire and other's nancial need. There is need to change men attitudes and subsequent behaviours. Men do not protect themselves because male attitudes
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tell them not to; while women do not protect themselves because men do not allow them to.
9.1.1. Behaviour change could play a greater role in reducing HIV infection If individuals could: 1. Postpone their rst sexual intercourse. 2. Practice safe sexual practices 3. Reduce the number the number of sexual partners 4. Prevent and treat STDs 5. Avoid traumatic sexual intercourse 6. Make sex a consensual activity, openly discuss sex issues etc.
9.1.2. Safe sex and safer behaviors
Practice abstinence.
Reduce the number of sexual partners to one.
Always use latex condoms with a water-soluble lubricant containing the spermicide nonoxynol 9 and do not reuse condoms.
Do not use cervical caps or diaphragms without using a condom as well.
Always use dental dams for oral female genital or anal stimulation.
Avoid anal intercourse because this practice may injure tissues.
Avoid manual - anal intercourse ( sting).
Do not ingest urine or semen.
Avoid having sex with people who are injecting drug users.
Engage in nonpenetrative sex such as body massage, social kissing (dry), mutual masturbation, fantasy, and sex lms.
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If female, avoid pregnancy if you or your sexual partner is HIV seropositive.
Inform prospective sexual partners of your HIV-positive status.
Notify previous and present sexual partners if you learn that you are HIV seropositive.
If HIV seropositive, do not have unprotected sex with another HIVseropositive person because cross-infection with another HIV strain can increase the severity of the disease.
Do not share needles, razors, toothbrushes, sex toys, or other bloodcontaminated articles.
If HIV seropositive, do not donate blood, plasma, body organs, or sperm
9.2. Role of Gender in HIV/AIDS Transmission Although women are making eorts towards equality with men, a lot of them still do not have control over their lives especially their bodies.
9.2.1. Cultural, social, biological and economic pressures make women more vulnerable HIV that men. 1. Men still dictate matters regarding sex - for example, when to have sexual intercourse irrespective of whether a woman wants it or not. Also use of condom relies on the man. 2. Girls have been taught to leave decision making on sex matters to males whose needs and demands are expected to dominate. 3. Male predominance often comes with intolerance for predatory and violent sexuality - this carries double standards whereby women are blamed or thrown out for in delity whether real or suspected while men are allowed to have multiple sexual partners. 4. Biological makeup and reproductive anatomy of the female body makes her to be more vulnerable to contract HIV than men - sex takes place inside the body of the woman and the female genitalia is prone to tears
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and wear. These tears and wears and/or sores provide entry route for the virus. 5. The female reproductive system is also in direct and longer contact with the male semen deposited during sexual intercourse. If the semen has HIV, then it becomes easier for her to contract the virus. 6. Poverty - failure to respect the human rights of girls in terms of equal access to school, training, employment opportunities etc. reinforces their economic dependence on men. A woman who is in a stable relationship and is economically dependent on her husband cannot aord to jeopardize his support even when she suspects that he is HIV positive. If she insists on a condom use she is accused of being unfaithful or the man reacts violently. 7. Prostitution-a lot of women go into prostitution as a way of income generating activity. A lot of them end up acquiring HIV/AIDS. For some women, prostitution is a choice while others are forced by circumstances into it to exchange sex for basic necessities of life for themselves and their children. 8. Cultural practices-a number of cultural practices have increased the vulnerability of women to contracting HIV. These include wife inheritance, polygamy, early marriages and resistance to condom use. 9. Social evils - they include rape, sodomy, homosexuality, premarital, extramarital sex, and drug and alcohol abuse. 10. Ignorance - majority of women are poorly educated and lack information on their bodies, HIV/AIDS and other sexually transmitted diseases. They are therefore unable to protect themselves.
A vulnerable woman is one who is lacking in power or control over her risk of HIV infection.
9.2.2. Remedy to above problem 1. Combating ignorance:
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(a) improve the access of girls to formal education, (b) ensure they have information on their bodies, HIV/AIDS and other STD's, and (c) equip them with skills to say NO to unsafe sex.
2. Provide women friendly services
(a) girls and women should have access to appropriate health care and HIV/STD prevention services, (b) make condoms and STD care are available where women don't feel embarrassed.
3. Make female condoms available - female condoms though expensive should be made available. 4. Build safer norms - support organizations advocating against behavioral traditions which have become deadly with the advent of HIV/AIDS e.g. genital mutilation, child abuse, rape, sexual coercion. 5. Educate boys and men to respect girls and women - this enables them to engage in responsible sexual behavior and to share their responsibility for protecting themselves, their partners and their children from HIV/AIDS and STDs. 6. Reinforce women's economic independence - increase and strengthen existing training opportunities for women, credit programmes, saving schemes and women's cooperatives and link them with AIDS prevention activities. 7. Reduce vulnerability through policy changes - policies from communities to national level must be reshaped if women's vulnerability to HIV is to be reduced. Human rights and legal rights should be improved.
9.3. Drug/Alcohol Use and Abuse and the Spread of HIV/AIDS A drug can be de ned as any substance that aects the function of living cells, used in medicine to diagnose, cure, prevent the occurrence of diseases
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and disorders, and/or prolong the life of patients with incurable conditions Drug abuse is characterized by taking more than the recommended dose of prescription drugs such as barbiturates (depressants) without medical supervision, or using government-controlled substances such as marijuana, cocaine, heroin, or other illegal substances. Legal substances, such as alcohol and nicotine, are also abused by many people. Abuse of drugs and other substances can lead to physical and psychological dependence. Drug abuse can cause a wide variety of adverse physical reactions. Long-term drug use may damage the heart, liver, and brain. Drug abusers may suer from malnutrition if they habitually forget to eat, cannot aord to buy food, or eat foods lacking the proper vitamins and minerals.
Individuals who abuse injectable drugs risk
contracting infections such as hepatitis and HIV from dirty needles or needles shared with other infected abusers. One of the most dangerous eects of illegal drug use is the potential for overdosing that is, taking too large or too strong a dose for the body's systems to handle. A drug overdose may cause an individual to lose consciousness and to breathe inadequately. Without treatment, an individual may die from a drug overdose. Drug addiction is marked by a compulsive craving for a substance. Successful treatment methods vary and include psychological counseling, or psychotherapy, and detoxi cation programs medically supervised programs that gradually wean an individual from a drug over a period of days or weeks.
Detoxi cation and psychotherapy are often
used together. The illegal use of drugs was once considered a problem unique to residents of poor, urban neighborhoods. Today, however, people from all economic levels, in both cities and suburbs, abuse drugs. drugs to relieve stress and to forget about their problems. may predispose other individuals to drug addiction.
Some people use Genetic factors
Environmental factors
such as peer pressure, especially in young people, and the availability of drugs, also in uence people to abuse drugs.
People with alcohol use disorders are
more likely to contract HIV than the general population.
Similarly people
with HIV are more likely to abuse alcohol in their life time. In persons already infected, the combination of heavy drinking and HIV has been associated with increased medical and psychiatric complications, delay in seeking treatment, poor HIV treatment outcome.
People who abuse alcohol are more likely to
engage in behaviors that place them at risk of contracting HIV. Heavy alcohol
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use has been correlated with a high risk sexual behaviors including:
Multiple sex partners
Unprotected intercourse
Sex with high risk partners
9.3.1. Relationship between drug use and HIV
Shared needles/syringes for use in drug application can carry HIV and hepatitis viruses.
Drug use is linked with unsafe sexual activity.
Infected blood drawn into the needle is infected along with the drug by the next user.
A recent study has shown that HIV can survive in a used syringe for at least 4 weeks.
A lot of people believe that sex and drugs should go together. Drug users might trade sex for drugs.
Others think that sexual activity is more enjoyable when they are using drugs.
Drug use including alcohol increases the chance of not using protection during sex, leads to acquiring/transmitting HIV/AIDS.
A lot of drugs interfere with the proper functioning of the antiretroviral drugs.
One who is a drug addict might forget to take his ARV therapy - delay in treatment and increment of viral load.
A probability of overdose which is fatal
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Exercise 11.
Revision Questions
Discuss gender vulnerability of HIV infection in females relative to male counterparts
Example
.
Discuss the eects of stigma and discrimination on the spread
of HIV/AIDS
Solution :
Stigma (attitude) can be de ned as a discrediting attribute that
is used to separate the aected persons or groups apart from the normalized orders, or an act of identifying, labeling or attributing undesirable qualities targeted towards those who are perceived as being shamefully dierent and deviant from the social ideal . Discrimination (act) is an action or treatment based on the stigma, sanction, harassment, scapegoat and violence based on infection or association with HIV/AIDS .
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Revision questions or guidelines 1. Using appropriate examples discuss the rights of people living with HIV/AIDs at the work place. 2. During Volutary Conselling and Testing explain how the health worker should conduct him/herself to ensure the rights of the person visiting that clinic are observed. 3. Sex education is a right for every youth.
Discuss in detail what this
entails. 4. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 10 Implications of Hiv/Aids And International Responses to the Hiv/Aids Pandemic Learning outcomes Upon completing this topic, you should be able to know:
Impacts of HIV on individuals, families, community
Demographic impacts - population
Multi - sectoral impact (Education, Agriculture, Economy, Health, Industry and Business)
Responses of African Governments to HIV - AIDS epidemic
Strategies adopted by the Kenyan government to ght the spread of HIV/AIDS
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10.1. To the individual
Feeling of hopelessness
Self pity
Depression
Suicidal thoughts
Shame
Anger
Denial
Revenge
Fear of death
Social withdrawal - segregation of infected
Opportunistic infections
Inability to work
Reduced life expectancy
Loss of job
Lack of faith in God or religion
Poverty due to medical expenses
Disruption of persons future plans
Discrimination at work place and social stigmatization
Change of sexual behavior
Poor relationship with spouse, children and relatives
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10.2. To the family
Marital instability and breakup - lack of peace in couples
Children are deprived of parental care and support
Sense of anticipating grief
Shame to the family
Loss of bread winner
Lack of emotional support/direction
Strained nances
Burden of children to the relatives and family friends
Orphans & vulnerable children have their growth aected, reduced access to basic education & increased risk of acquiring HIV due to lack of parental guidance
10.3. To the community
Reduction of productivity
Development retardation
Expensive funerals
High hospital occupancy
Financial burden for insurance companies
Increase in number of street children
Increased infant mortality rate
Dependency ratio goes up
Increased widows, widowers & orphans
Loss of many lives (human potential)
Increased diseases which were at one time in control e.g. TB
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10.3.1. How to solve negative eects
Creation of homes for orphans
Provision of free education to orphans
Introduction of Voluntary Counseling and Testing Centers
Adoption of orphans in the community
Destigmatization
10.4. Multi - Sectoral Impacts of HIV/AIDS 10.4.1. Impact on Industry and business sector
Industry and business sector forms the basis for production and supply.
Labour is required for this production to occur
HIV/AIDS has eect on labour due to:- increased absenteeism, decreased productivity, reduced number of employees through death, loss of accumulated skills and declining morale.
Increased medical costs for business with medical schemes
Declining productivity and increased medical costs results in declining pro ts
HIV/AIDS indeed reduces the productivity of the labour force.
10.4.2. Impact on agriculture
Agriculture is the mainstay of Kenya's economy, followed by tourism sector
Lower productivity in farming areas due to illness, absenteeism, death and loss of farming skills
Less land is cultivated
Less labour - intensive crop production
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Loss of household and farm assets - this is due to diverted time of family members to taking care of the sick and attending funerals.
Less crop production
Less livestock production
Decline in agricultural income and food production and increased food insecurity
Labour productivity is reduced in commercial farming as well as subsistence farming.
10.4.3. Impact on education
Increased morbidity
Absenteeism and attrition of teachers
Reduced number of school-aged children attending school
Poor performance in classroom
These result in decline in quality of education and impose higher cost on education system.
Pupils are afraid of being taught by infected teachers
Teachers reported as dying of AIDS are not replaced
Loss of trained and experienced teachers
Interruption of teaching programs due to illnesses
Resources available to support education are diverted to meet HIV/AIDS related needs
Children from aected families absent themselves because they take care of the sick
Poor attendance and increased number of school drop outs because of aected families and death of parents.
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10.4.4. Impact on health sector
Increased demand for health services due to the number of infected persons
More health resources and workforce are diverted to HIV/AIDS treatment
Shortage for other health care needs
Half or more beds in public hospitals are occupied by HIV patients
Reduced morale of health workers because HIV patients respond poorly to treatment or die
HIV infected health workers may have low productivity and morale
Anti-Retroviral Therapy (ART) is costly
Laboratory tests to monitor patients are also costly
Costs of treating opportunistic infections and prophylaxis costs.
10.4.5. Impact on economic growth
Economic growth is dependent on sustained increase in productive capacity and real output resulting in growing national income
Labour, capital and technical progress determine economic growth
HIV/AIDS aect labour and capital investments
It aects mostly the most productive members of population thus reverses growth in labour supply
Reduces productivity of infected and aected workers
Skilled persons die of AIDS reducing economic growth
Reduced level of domestic savings and investment (crucial for capital formation) due to medical expenses.
Reduced income and increased poverty imply decreased purchasing power of households thus decreased demand for goods and services
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10.5. Responses of African Governments to HIV - AIDS epidemic 10.5.1. Formation of institution to coordinate and ght HIV pandemic The AIDS programme secretariat was established to control the HIV/AIDS under the guidance of National AIDS committee(NAC). AIDS programme secretariat was elevated to the status of a National HIV/AIDS programme (NACP) under the ministry of Health. The National HIV/AIDS programme and the National STDs control programme (NSTDCP) were merged in 1994 to form the National HIV/AIDS and STD programme (NASCOP) which assumed a stronger coordinating role, especially of NGO's and religious groups.
10.5.2. Declaring HIV a national disaster The government released surveillance data and hosted the rst National conference on HIV/AIDS. The minister of health rst declared HIV/AIDS a national crisis while the government and international development partners initiated social and economic impact assessments. In November 1999, the government declared HIV/AIDS a national disaster.
This was followed by the forma-
tion and establishment of a National HIV/AIDS Control Council (NACC).The launch of the Kenya National HIV/AIDS plan in December 2000 was the advent of a new phase of bold war against the HIV/AIDS disaster.
10.5.3. Some of the strategies adopted by the Kenyan government to ght the spread of HIV/AIDS Kenya war on HIV/AIDS took a new dimension on 1st December 2003 following the launch of constituency AIDS control committees (CACC) by his Excellency President Mwai Kibaki. The launching was done during the worlds AIDS day commemoration at KICC. -The o cial launch of the National HIV/AIDS Behavior change communication strategy phase one campaign was also done the same day by the President. The strategy focuses on supporting people who are at a risk of contracting AIDS by providing accurate information through a range of media outlets.
Pamoja Tuangamize Ukimwi was selected as a
campaign slogan. In March 2004, the President launched the country total war on HIV/AIDS and formed a cabinet committee which He chairs. The committees' approach
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lies in mobilizing communities in every corner of the country to eectively ght the AIDS pandemic. The committee discussions revealed the need to include care for those orphaned by AIDS and the provision of drugs for those infected. Some of the strategies adopted by the Kenyan government to ght the spread of HIV/AIDS includes: 1. Public educational campaigns: The government through its state owned media has set up sensitization programme to try and educate the public on the dangers of the disease and also advise them to stay healthy without contracting the disease. This is done through plays; poetry and reality show programs where HIV/AIDS individuals take the opportunity to air their views and encourage others to take measures to avoid contracting the disease.
The government has also gone step ahead in creating
awareness on AIDS prevention using other channels. This includes the use of billboards, posters, public lectures, pamphlets, performing AIDS groups etc. The government has also through its o cials advocated the need to sensitize people through community barazas where government o cials get the chance to give out the much needed information on the prevention of AIDS. 2. HIV/AIDS seminars and workshops: These are opened to anybody willing to attend and they are aimed at strengthening prevention activities. Through these seminars and workshops, people are educated and enlightened by professionals on the ways of contracting the virus and the consequences o0f the disease. People are encouraged to raise questions which are answered frankly and elaborated. These are also supplemented by lms concerning HIV/AIDS and STDs. 3. Mainstreamed HIV/AIDS lessons in formal education system: HIV/AIDS has become a core unit that is studied in primary schools, secondary schools, middle level colleges and universities. Students gain knowledge on the mode of transmission, prevention and control. This has helped in the reduction of spread of HIV since the most sexually active Kenyans, the youths are taught about the dangers of casual behaviors and unprotected sexual intercourse.
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4. Destigmatization campaigns: The government of Kenya through education has helped in reducing stigmatization as many people now takes this as any other disease.
This has helped to remove stigma label on
those infected and hence are no neglected. This has encouraged free talk about AIDS and thus created awareness amongst Kenyans. 5. Free distribution of condoms: The government has taken the responsibility of distributing condoms free of charge.
These are distributed in
hospitals, during rallies on anti-HIV/AIDS campaign. The government encourages correct and consistent use of latex condoms during sexual intercourse. In this regard the government has zero rated tax on condoms and other preventive devices to ensure that its citizen can all have access to all available preventive measures. 6. Provision of treatment to HIV/AIDS patients: The government plays a role in availing treatment to HIV/AIDS patients. It provides free or subsidizes ARV drugs and other health services to people suering from HIV/AIDS. The government has taken the initiative to help prevent mother to child transmission. HIV positive mothers are given antiretroviral drugs during pregnancy and delivery.
This includes AZT which
helps in the reduction of the viral load. HIV positive mothers are also encouraged to undertake caesarian section instead of normal delivery. The government has also encouraged HIV positive mothers neither to donate breast milk to milk banks nor to express their breast milk to be bottle fed to their babies. 7. Provision of VCT centers all over the country: The government has established and opened VCT centers all over the country. VCT services are oered free of charge in most government health facilities. This has enabled most Kenyans to know their HIV status and through guidance and counseling, they have been taught on how to live positively for those aected and how to stay negative for those who are HIV negative. In VCT centers clients are taught about contracting, transmission, prevention and control. 8. Discouragement of detrimental socio-cultural practice: The government
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in conjunction with NGO's is trying to ght against socio-cultural practices that have become deadly with the advent of HIV/AIDS. They have been at the forefront of trying to eradicate such practices which includes FGM, circumcision done the traditional way, wife inheritance and early marriages. 9. Gender advocacy: The government is also advocating for gender equality and thus is teaching women on their basic rights and more so not to be sexually abused. This has empowered women and exposed them to the current world where they are recognized and respected equally as men. The government has enhanced laws against violence on women and other vulnerable groups in the society including HIV AIDS individuals to protect them from victimization. Tough laws have been enacted for imprisonment of anyone involved in rape case.
This has gone way in
reducing the spread of HIV/AIDS. 10. Poverty eradication: The government has been at the forefront of trying to eradicate poverty. It has started constituency development fund through which constituencies throughout the country receive fund from the central government and channel them to projects that help elevate the living standards of the local by creating income-generating activities. The government has also permitted formation and operations of NGO are that help people at grass root ght poverty. Some of these NGO's cater for vulnerable groups in the society.
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Exercise 12.
Revision Questions
Describe programs initiated by public health o cials to protect and improve the health of the community
Example
.
Discuss factors that have contributed to the high prevalence of
HIV/AIDS in Sub-Saharan Africa
Solution :
Premarital sex - sex before marriage, involves both fornication and
adultery.
Extra marital sex - involves having sex besides the matrimonial
spouse. Corporal adornment - of body parts which involves piercing of some body parts such as ear, nose, tattooing portions of the body etc. Cohabitation - trial marriage.
Sex for ritual purposes - these arise from the belief in the
powers of an external force, usually in the form of a spirit which can befall a person if some prescribed traditional rituals are not carried out.
Festival
seasons - during certain occasions such as Christmas, valentine day etc, there is a strong behavior towards sexual involvement. Sex for expediency - this is a relationship for the purpose of material gain of one kind of another.
Sex
for livelihood - this means commercial sex work, and involves exchange sex for money. Prostitution is the old name given to this kind of activity. Sexual orientation (Homo sexual and lesbianism) - these kinds of sexual orientation have emerged in urban centers even though they are conducted clandestinely and are strongly disproved.
Resistance to condom use - the use of condom
is a new norm in sexual union among African. It is culturally unknown and the suggestion of its use suggests sign of mistrust.
Drug and alcohol use
and abuse - use of hard drugs and alcohol predisposes those involved to risky sexual behavior in the context of HIV/AIDS. Internet and pornography - these are stimulating sexually to the mind and individuals especially the youngster may be tempted to copy and put into practice what they view thus becoming vulnerable to contract HIV/AIDS. Lack of recreational facilities - due to over development in urban centers, there is no longer space for playgrounds and other recreational facilities. The youth become idle and to reduce idleness they engage in risky behaviors that predisposes them to HIV/AIDS infection. Social stigma - because of this, HIV positive individual hide their status and behave normally while they go on infecting other people. Male and female circumcision - the same knife is used repeatedly without sterilization this leading to risk of blood contamination wit HIV. Polygamy - this practice is resilient in a number
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of communities. Given the evidence that many sexual partner increases one chances of being exposed to HIV, polygamy and extramarital relationships which are culturally tolerated play a part in the spread of HIV/AIDS. Spouse inheritance - this is a cultural practice which promotes the exchange of sexual partners after death in a family. In its formal sense it involves marrying o the surviving partner to a relative of the deceased. Given the fact that most cases of HIV transmission are as a result of heterosexual relationships and that AIDS as the cause of death is usually not disclosed to the relatives, inheritance of spouses has pose high risk of exchanging the HIV virus, thus feeling the HIV pandemic.
Cultural taboos - people attribute HIV/AIDS to witchcraft or a
curse arising from violating some cultural taboos. Most people tend to believe that HIV/AIDS does not exist.
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Revision questions or guidelines 1. The eect of HIV epidemic has prompted the Kenyan Government ti initiate various programs to reduce the spread of HIV among its citizens. Discuss this statement. 2. Discuss the impact of HIV on education 3. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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Solutions to Exercises Exercise 1.
The vaccine used in the program then was discovered in the
stores of the original place that developed it. This was subsequently analyzed. It was announced that no trace had been found of either HIV or chimpanzee SIV. A second analysis con rmed that only macaque monkey kidney cells, which cannot be infected with SIV or HIV, were used to make Chat and not chimpanzee's as earlier suggested. While this is just one phial of many, most have taken its existence to mean that the OPV vaccine theory is not possible. The fact that the OPV theory accounts for just one (group M) of several dierent groups of HIV also suggests that transferal must have happened in other ways too. The nal element that suggests that the OPV theory is not credible as the sole method of transmission is the argument that HIV existed in humans before the vaccine trials were ever carried out.
Exercise 2.
Exercise 1
HIV is the human immunode ciency virus that causes AIDS
(acquired immunode ciency syndrome). When HIV infects someone, the virus enters the body and begins to multiply and attack immune cells that normally protect us from disease. It's only when someone with HIV begins to infections and illnesses that they're diagnosed with AIDS.
Exercise 3.
Exercise 2
Fertility myth - Common belief that one engage in sex to enhance
fertility in future. This not true. People have to multiply to ll the earth, a literal translation of a biblical command but people are supposed to multiply in spiritual sense. This is a corruption of the bible. Health Myth - abstaining from sex leads to sickness and madness, nobody has ever fallen sick or become mad for not engaging in sexual intercourse. Having a venereal disease is considered a badge of honor that con rms manhood. Venereal diseases confers no honor to any man. Venereal disease is cured if the man has sex with a virgin. This is not true.
On the contrary the Venereal disease suerer will transmit the
disease to the virgin. Special food and exercise will make the penis grow big. This is not true. Whatever that is good for other body parts is also good for sex organs.
Men have stronger sexual urges than women.
believed to be boundless and irrepressible.
Men sex drive is
This is not true.
Sexual urge is
equal in both the sexes. It is generally said that Africans are promiscuous This is not true. Promiscuity is not necessary an African trait has other races have
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promiscuous people too. A man cannot be satis ed by one woman. This not true. One can't get pregnant during the rst sex intercourse. Common believe that there is a grace period between the rst sexual encounter and getting pregnant - like the payment schedule on credit card.
This one isn't true.
One can't get pregnant during unprotected sex if the man pulls out before he ejaculates. This is not true. Some small amounts of sperm containing semen may be deposited in the vagina before ejaculation. Other remain in the urethra after ejaculation and can fertilize an ova. A woman is not considered to be a female if she cannot conceive a child.The femininity of a person is not judged by the ability to conceive a child.
There are other criteria.
Common belief
that virginity brings problems during birth. This is not true. Imparting sex education to youngsters will lead them to promiscuity. Educating the young on sex and sexual behaviour helps them to develop a healthy and positive attitude towards sexuality .
Exercise 4.
Exercise 3
The immune system is responsible for body defense against attack
from pathogens. It is made up of white blood cells which include granulocytes such as neutrophils and basophils, and agranulocytes such as monocytes and lymphocytes. T-helper lymphocytes have a CD4+ marker that the HIV uses for entry into the cell and replicates. T-helper lymphocytes are important in immune regulation because when they are activated they recruit other immune cell involved in immune responses. HIV uses the CD4+ cells to replicate and produce more viral particles. CD4 are killed and destroyed as viral production progresses.
Cytotoxic T-lymphocytes with CD8+ marker target any virally
infected CD4+ cells and kills them. Macrophages which have a CD4+ marker too act as reservoir and are also killed by cytotoxic. As virtually infected cells are killed by cytotoxic T-lymphocytes and more of the CD4+ cells destroyed as a result of viral replication, their numbers goes down. The immune system is depleted of these crucial cells involved in body defense and becomes vulnerable to attack by opportunistic pathogens.
Exercise 4
Exercise 5. Entry in the CD4 + - Binding of GP 120 to CD molecule allows it to bind to co-receptor causing fusion of viral and cell membrane leading to entry of virus into cell.
Reverse transcription - Conversion of viral RNA
into viral DNA under the in uence of reverse transcriptase in the cytoplasm.
Integration - Viral DNA moved into cell nucleus where it is integrated with 137
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host cell chromosome under the in uence of intergrase.
Transcription - Pro-
duction of new viral mRNA molecules for production of viral RNA involving
Translation - Viral mRNA is transported to the cytoplasm to produce viral structural proteins under the in uence of HIV Proteins. Assembly and budding - Newly made HIV core proteins enzymes and genome RNA gather inside cell and they bud o. Maturation - The core of the virus host cell enzymes.
is immature and therefore un-infectious protease breaks the long protein chains causing viral particles.
Exercise 6.
Exercise 5
Primary HIV infection - This is the initial stage where one
obtains the virus through the various modes of transmission. Window period - This stage of infection lasts for a few weeks to about 3 months and is often accompanied by a short u-like illness or no signs. HIV cannot be detected in blood screening although HIV is present in blood & the blood in not 100% free of HIV. During this time a person can still transmit the virus to another person. It's the most crucial stage. Sero conversion - This is the development of the anti-bodies.
Immune system begins to respond to HIV by producing
HIV antibodies and cytotoxic lymphocytes. If an HIV antibody test is done before seroconversion is complete then it may not be positive. In this stage a person may have u like illnesses, fever, fatigue, sore throat, joint pains & lymphadenopathy.
Some will not experience any illnesses at this stage.
Clinical asymptomatic HIV infection/ Latent phase - The presence of HIV without major symptoms. Although there may be swollen glands. The level of HIV in the peripheral blood drops to very low levels but people remain infectious and HIV antibodies are detectable in the blood, so antibody tests will show a positive result. HIV is not dormant during this stage, but is very active in the lymph nodes. Large amounts of T helper cells are infected and die and a large amount of virus is produced. This period can last for many years (5 15 years).
Symptomatic HIV infection/AIDS Related Complex (ARC)
phase - Over time the immune system loses the struggle to contain HIV due to the following main reasons: The lymph nodes and tissues become damaged or 'burnt out' because of the years of activity; HIV mutates and becomes more pathogenic, i.e. stronger and more varied, leading to more T helper cell destruction; The body fails to keep up with replacing the T helper cells that are lost. It varies between people & depends on a length of factors. Progression
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of HIV to AIDS - As the immune system becomes more and more damaged the illnesses that present become more and more severe leading eventually to an AIDS diagnosis. It's the most advanced stage of HIV infection. At this time when CD4 cell count has gone down below 200CD4 cells/ml, HIV develops to one or more severe opportunistic infections or cancer.
Exercise 6
Exercise 7. The Enzyme-Linked Immunosorbent Assay
(ELISA) -
Identi es antibodies directed speci cally against HIV. ELISA test does not establish a diagnosis of AIDS, rather it indicates that the person has been exposed to or infected with HIV. People whose blood contains antibodies for HIV are said to be sero positive.
HIV antibodies do not reach detectable
levels in the blood for one to three months.
Window period is the time
during which antibody detection using Elisa is negative. In some cases it may take even 6 months for the antibody levels to get high enough for detection. The
Western blot assay
is another test that can identify HIV antigens and
is used to con rm sero positivity as identi ed by the ELISA. This is a method that detects very low antigen levels such that one may test HIV negative by ELISA but test positive through western blot.
Babies born of HIV mother
have antibodies to HIV that were passed on during pregnancy through the placenta. However these antibodies diminish with time such that by 15 months the child may test negative. Use of Western, blot con rms presence of HIV antigen and this rules out whether babies are positive because of HIV itself or because of maternal antibodies.
PCR is also used to detect HIV in high-risk
seronegative people before the development of antibodies, to con rm a positive ELISA, to screen neonates, and to determine the exact strain of virus that is present.
CD4+Cell count - Once a patient is diagnosed positive the extent of
damage to the immune system is determined by CD4+ cell count (T-helper cell count). The number of CD4 cells present is a direct indicator of the immune system's ability to ght o opportunistic infections. The test to measure CD4 cells requires a sample of blood to be taken and measurement is made of the number of CD4 cells in a cubic milliliter of blood and will give a picture of the health of the immune system-whether it is improving or declining. The CD4 count of a person who is not infected with HIV may lie anywhere between 500 and 1200.A drop in an HIV positive persons CD4 count usually occurs over a number of years.
A CD4 count between 500 and 200 indicate that
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some damage to the immune system has occurred and a count below 350 or rapid decline is an indication that one should consider anti-HIV treatment.
Measuring viral load
- Measuring viral load is essential to determine how
active the viral replication is if one is taking anti-HIV medication, then it is also a direct indicator of how successful it is in suppressing viral replication. The viral load test requires the collection of a blood sample and estimates the number of HIV particles in the sample by looking for HIV genes. The level of viral load is generally seen as a good indicator of whether to start ant-HIV treatment. An undetectable viral load is an indication that both the risk of developing AIDS and the risk of developing drug resistance has been reduced. A high viral load is an indication of high levels of HIV in body uids while undetectable viral load indicates a reduction in levels of HIV in these uids but the risk of transmitting the virus is still present.
Exercise 8.
Exercise 7
VCT has taken a central role in enlightening and guidance of
HIV/AIDS disease. Involve testing and availing the results to people in minutes. Before testing the people are prepared rst for both positive and negative results before allowed to know their status. Importance of knowing one's HIV status includes: Preventing the uninfected person from contracting the disease.
Enhancing abstinence for the infected helps in controlling the disease
through self awareness and putting up ways on how to abstain or get involved in safe sex. Counseling also helps in ensuring reduced spread of the virus by those people who have been infected but had not shown symptoms. Counseling infected people, majority of who have lost hope, helps in ensuring positive living. Help to reduce the revenge attitude for those innocently infected and may opt to die with many or commit suicide. Counseling enables the public who includes the relatives of the infected to stop stigmatizing those infected to be able to live normal lives knowing that someone cares for them. Testing also helps the government to keep statistics on the prevalence of the disease hence policy development or strategic planning. Prevention involves tackling the most important modes of transmission. sexual transmission.
Exercise 9.
Discuss brie y how to prevent Exercise 8
Early and eective treatment of STIs decreases the amount of
HIV in genital secretions and reduces the risk of its spread to other sexual partners. Early treatment also reduces the risk of contracting HIV from infected
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partners. Furthermore, early diagnosis and treatment of STIs are important because they can prevent serious complications, such as infertility, ectopic pregnancy, genital cancer, blinding eye disease, and major nervous system infections in infants, that can occur as a result of an untreated STI. Exercise 9
Exercise 10.
There is a treatment called post-exposure prophylaxis (PEP)
for HIV. PEP is a month-long course of drugs that may prevent a person from becoming infected with HIV if they begin treatment within three days of exposure to HIV. If you may have been exposed, contact a health service as soon as possible for treatment. See the `Further Information' section at the end of this booklet for service details for PEP.
Exercise 11.
Exercise 10
Men still dictate matters regarding sex - for example, when to
have sexual intercourse irrespective of whether a woman wants it or not. Also use of condom relies on the man.
Girls have been taught to leave decision
making on sex matters to males whose needs and demands are expected to dominate. Male predominance often comes with intolerance for predatory and violent sexuality - this carries double standards whereby women are blamed or thrown out for in delity whether real or suspected while men are allowed to have multiple sexual partners. Biological makeup and reproductive anatomy of the female body makes her to be more vulnerable to contract HIV than men - sex takes place inside the body of the woman and the female genitalia is prone to tears and wear. These tears and wears and/or sores provide entry route for the virus. The female reproductive system is also in direct and longer contact with the male semen deposited during sexual intercourse. If the semen has HIV, then it becomes easier for her to contract the virus. Poverty failure to respect the human rights of girls in terms of equal access to school, training, employment opportunities etc. reinforces their economic dependence on men. A woman who is in a stable relationship and is economically dependent on her husband cannot aord to jeopardize his support even when she suspects that he is HIV positive. If she insists on a condom use she is accused of being unfaithful or the man reacts violently. Prostitution-a lot of women go into prostitution as a way of income generating activity.
A lot of them
end up acquiring HIV/AIDS. For some women, prostitution is a choice while others are forced by circumstances into it to exchange sex for basic necessities
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of life for themselves and their children. Cultural practices-a number of cultural practices have increased the vulnerability of women to contracting HIV. These include wife inheritance, polygamy, early marriages and resistance to condom use. Social evils - they include rape, sodomy, homosexuality, premarital, extramarital sex, and drug and alcohol abuse.
Ignorance - majority of
women are poorly educated and lack information on their bodies, HIV/AIDS and other sexually transmitted diseases. They are therefore unable to protect themselves.
Exercise 12.
Exercise 11 Vaccination - This is the process of making the body resistant
to a speci c disease by using a vaccine Vaccination programs protect people against disease.When small outbreaks of infectious disease threaten to grow into epidemics, public health o cials may initiate new vaccination programs. Rural and Urban Health Clinics - Public health agencies operate local clinics that provide free or reduced-cost medical services to individuals, especially infants and children, pregnant and nursing women, people with drug abuse problems, physical disabilities, and other conditions.
Public health clinics
routinely screen patients for a number of infectious diseases Each clinic tracks the incidence of certain communicable diseases in its area, and reports this information to national and international public health o ces. Disease Tracking and Epidemiology - Threats to public health concerns change over time and epidemiologists and other o cials continuously evaluate epidemiological trends to determine how best to meet future public health needs. Epidemiologists and other public health o cials attempt to break the chain of disease transmission by notifying people who may be at risk for contracting an infectious disease Public health o cials ensure that infected people complete treatment programs, so that the diseases are completely eliminated and the patients are no longer carriers of the infection. Sanitation and Pollution Control Disease-causing organisms are often transmitted through contaminated drinking water.
The single most eective way to limit water-borne diseases
is to ensure that drinking water is clean and not contaminated by sewage. I In many parts of the world, public health o cials establish sewage disposal and solid waste disposal systems, and regularly test water supplies to ensure they are safe. Environmental pollution is another preventable cause of disease and disability, and in most countries public health o cials address the adverse
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health eects of air pollution and water pollution. Public health o cials may work in conjunction with pollution control organizations to establish and enforce pollution limits and advise the general population when pollution levels exceed safe limits.
Medical Research Cadres of doctors and scientists work
in laboratories around the world to establish new ways to prevent, diagnose, treat, and cure disease and disability. Scientists and doctors employed by the government conduct some biomedical research in public health facilities to nd better ways to protect human health. Public Education Campaigns Many diseases are preventable through healthy living, and a primary public health goal is to educate the general public about how to prevent noninfectious diseases.. Health promotion encourages people to take advantage of early diagnostic tests that can make the outcome of disease more favourable e.g. early breast cancer detection .
Exercise 12
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SCHOOL OF OPEN, DISTANCE AND eLEARNING IN COLLABORATION WITH FACULTY OF SCIENCE
DEPARTMENT OF ZOOLOGY P.O. Box 62000, 00200 Nairobi, Kenya
SZL 2111 HIV/AIDs
LAST REVISION ON April 17, 2013 K. O. OGILA ([email protected])
JOMO KENYATTA UNIVERSITY OF AGRICULTURE & TECHNOLOGY SCHOOL OF OPEN, DISTANCE AND eLEARNING P.O. Box 62000, 00200 Nairobi, Kenya E-mail: [email protected]
SZL 2111: HIV/AIDs
LAST REVISION ON April 17, 2013
SZL2111 HIV/AIDs
This presentation is intended to covered within one week. The notes, examples and exercises should be supplemented with a good textbook. Most of the exercises have solutions/answers appearing elsewhere and accessible by clicking the green Exercise tag. To move back to the same page click the same tag appearing at the end of the solution/answer.
Errors and omissions in these notes are entirely the responsibility of the author who should only be contacted through the
Department
of Curricula & Delivery (SODeL) and suggested corrections may be e-mailed to [email protected].
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SZL 2111: HIV/AIDs Course description General introduction: Public health and hygiene, human reproductive system, sex and sexuality.
History of sexually transmitted diseases (STDs); History
of Human Immunode ciency virus/ Acquired Immune de ciency Syndrome (HIV/AIDS), Comparative information on trends, global and local distribution, Justi cation of importance of course. Biology of HIV/AIDS; Overview of immune system, natural immunity to HIV/AIDS. The AIDS virus and its life cycle, disease progression, transmission and diagnosis.
Discordant cou-
ples. Treatment and Management; nutrition, prevention and control; Abstain, Be faithful, Condom use, Destigmatize HIV/AIDS (ABCD) methods and antiretroviral drugs and vaccines. Pregnancy and AIDS. Management of HIV/ AIDS patients. Social and cultural practices: Religion and AIDS. Social stigma on HIV/AIDS. Behavioral change. Voluntary Counseling and Testing Services. Gender and HIV/AIDS. Drug and alcohol abuse and HIV/AIDS. Poverty and AIDS. Families and AIDS orphans. Government policies: Global policies of AIDS. Legal rights of AIDS patients. AIDS Impact: Family /society setup, population, agriculture, education, health, industry, development, economy and other sectors.
Prerequisite:
none
Course aims 1. To bring about behavioral change 2. To prevent HIV/AIDS and reduce the threat it poses to youth/students 3. To promote HIV/AIDS education as a means of producing better and more integrated sense of health education in the student
Learning outcomes Upon completion of this course you should be able to know; 1. Biology of HIV
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2. Transmission of HIV 3. Disease progression and symptoms 4. Treatment of HIV/AIDs Various strategies of managing of HIV/AIDs 5. How to prevent and control of HIV/AIDs 6. Social and cultural practices that contribute to spread of HIV/AIDs 7. Policies and rights of people living with HIV/AIDs 8. Implications of HIV/AIDs on various sectors
Instruction methodology
Lectures: oral presentation generally incorporating additional activities e.g writing on chalk board, exercises, class questions and discussions or student presentation.
Tutorials to give the students more attention.
Assignments and Demonstrations.
Assessment information The module will be assessed as follows;
10% of marks from two (2) assignments to be submitted online
20% of marks from two written CAT to be administered at JKUAT main campus or one of the approved centres
70% of marks from written Examination to be administered at JKUAT main campus or one of the approved centres
v
Contents 1 General introduction
2
1.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
1.2
Justi cation of the course
3
1.2.1
. . . . . . . . . . . . . . . . . . . .
Reasons for HIV/AIDS education/ why train in HIV/AIDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
1.3
De nition of Terminologies . . . . . . . . . . . . . . . . . . . .
5
1.4
Public Health and Hygiene . . . . . . . . . . . . . . . . . . . .
7
1.4.1
. . . . . . . . . .
7
Vaccination . . . . . . . . . . . . . . . . . . .
7
Rural and Urban Health Clinics
8
Disease Tracking and Epidemiology
Sanitation and Pollution Control
Medical Research
Public Education Campaigns
Public health programs may include:
. . . . . . . . . . . .
8
. . . . . . .
8
. . . . . . . . . . . . . . .
8
. . . . . . . . .
9
. . . . . . . . . . . . . . . . . . . . . . . . . . .
9
1.5
Types of HIV
1.6
Origin, Theories and History of HIV/AIDS
. . . . . . . . . .
11
. . . . . . . . . . . . . . . . . . . .
12
1.6.1
Mysterious origins
1.6.2
Religious Theories (God's wrath and witch craft)
. . .
12
1.6.3
Monkey origin theories . . . . . . . . . . . . . . . . . .
13
Hunter theory
13
Oral Polio Vaccine (OPV) theory
. . . . . .
13
The contaminated needle vaccine
. . . . . . .
14
The colonialism theory
. . . . . . . . . . . .
15
. . . . . . . . . . . . . . . . .
1.6.4
The conspiracy theory
. . . . . . . . . . . . . . . . . .
15
1.6.5
The calculated theory
. . . . . . . . . . . . . . . . . .
15
2 Sex education and Human sexuality vi
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2.1
2.2
What is sex education? . . . . . . . . . . . . . . . . . . . . . .
20
2.1.1
Aims of sex education
20
2.1.2
Myths surrounding sexuality
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
Sexually Transmitted Diseases . . . . . . . . . . . . . . . . . .
20
2.2.1
How do you know that you have an STD?
. . . . . . .
21
2.2.2
How STDs are transmitted . . . . . . . . . . . . . . . .
21
Factors that enhance chances of getting infected with STD . . . . . . . . . . . . . . . . . . . .
2.2.3
Prevention and Control of STIs
. . . . . . . . . . . . .
23
Importance of early diagnosis and treatment .
23
2.2.4
Basic information on some common STDs
2.2.5
Relationship between HIV and Sexually transmitted infections
. . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
3 The Immune system 3.1
22
23
28
32
Overview of the Immune System
. . . . . . . . . . . . . . . .
33
3.1.1
The bone marrow
. . . . . . . . . . . . . . . . . . . .
33
3.1.2
Types of Immunity . . . . . . . . . . . . . . . . . . . .
33
Innate/ Inborn/Natural/Non-speci c immunity; . . . . . . . . . . . . . . . . . . . . . . . . .
33
Acquired/ Adaptive / Speci c Immunity
. .
34
Cells of the Immune System . . . . . . . . . .
35
Stages in an immune response . . . . . . . . . . . . . .
38
Recognition stage . . . . . . . . . . . . . . . .
38
Proliferation stage
. . . . . . . . . . . . . . .
39
Response stage
. . . . . . . . . . . . . . . . .
40
Eector stage . . . . . . . . . . . . . . . . . .
40
3.1.4
Role of antibodies in Humoral Immune Responses . . .
41
3.1.5
Types of Immunoglobulins . . . . . . . . . . . . . . . .
42
3.1.6
Cellular (or cell mediated) immune response . . . . . .
42
Role of T lymphocytes . . . . . . . . . . . . .
43
Roles of null lymphocytes and natural killer
3.1.3
cells in cellular immune responses . . . . . . . 3.1.7
Complement System
. . . . . . . . . . . . . . . . . . .
44 45
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3.2
Immunode ciency
. . . . . . . . . . . . . . . . . . . . . . . .
3.2.1
Autoimmune disorders
3.2.2
Neoplastic disease
3.2.3
Chronic illness and surgery
3.2.4
Special problems
3.2.5
45
. . . . . . . . . . . . . . . . . .
47
. . . . . . . . . . . . . . . . . . . .
48
. . . . . . . . . . . . . . .
48
. . . . . . . . . . . . . . . . . . . . .
49
Role of immune system in HIV pathogenesis . . . . . .
49
4 Biology of HIV
53
4.1
Nature of HIV . . . . . . . . . . . . . . . . . . . . . . . . . . .
54
4.2
The Structure of HIV . . . . . . . . . . . . . . . . . . . . . . .
54
4.3
The Life Cycle of HIV/ HIV Replication
56
. . . . . . . . . . . .
5 Disease progression and symptoms 5.1
5.2
Introduction
60
. . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.1
Exposure vs. Infection
5.1.2
Infection vs. Disease
Stages of HIV Infection
. . . . . . . . . . . . . . . . . .
61
. . . . . . . . . . . . . . . . . . .
61
. . . . . . . . . . . . . . . . . . . . .
62
5.2.1
Primary HIV infection
. . . . . . . . . . . . . . . . . .
62
5.2.2
Clinical asymptomatic HIV infection/ Latent phase . .
62
63
5.2.3
Initial Infection Symptoms include:
. . . . .
Symptomatic HIV infection/AIDS Related Complex (ARC) phase
. . . . . . . . . . . . . . . . . . . . . . . . . . .
63
5.2.4
Progression of HIV to AIDS . . . . . . . . . . . . . . .
64
5.2.5
Other Complications in HIV Patients
65
5.2.6
Factors that lead to faster development of HIV infection
. . . . . . . . .
to full- blown AIDs . . . . . . . . . . . . . . . . . . . . 5.3
Opportunistic Infections
. . . . . . . . . . . . . . . . . . . . .
6 Transmission and diagnosis of HIV 6.1
6.2
61
Transmission of HIV
66 67
72
. . . . . . . . . . . . . . . . . . . . . . .
6.1.1
Modes of HIV Transmission
6.1.2
Factors that increase chances of MTCT/ Determinants
75
6.1.3
Prevention of MTCT (PMTCT)
. . . . . . . . . . . .
76
. . . . . . . . . . . . . . . . . . .
77
Diagnosis of HIV and AIDs 6.2.1
. . . . . . . . . . . . . . .
73
The Enzyme-Linked Immunosorbent Assay (ELISA)
.
73
77
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6.3
6.2.2
The Western blot assay
. . . . . . . . . . . . . . . . .
77
6.2.3
PCR
. . . . . . . . . . . . . . . . . . . . . . . . . . .
77
6.2.4
CD4+Cell count
6.2.5
Measuring viral load
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STIs, STDs, FGM and HIV/AIDS
. . . . . . . . . . . . . . .
6.3.1
Common examples of STIs/ STDs
. . . . . . . . . . .
6.3.2
Relationship between HIV & STDs/STIs
6.3.3
Dangers/ risks of STDs/STIs
6.3.4
Why teenagers don't seek treatment
6.3.5
FGM (Female Genital Mutilation)
80
. . . . . . . . . .
80
. . . . . . . . . . .
81
. . . . . . . . . . . . . . . . .
81
Eects of FGM leads to conditions that favours . . . . . . . . . . . . . . . . . .
Prevention and control of mother to child transmission
7.2
Prevention and control of transmission through blood and other
. . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
85
85
. . . . . . . . . . . . . . . . .
86
Ways in which HIV cannot be transmitted . . . . . . .
86
Treatment of HIV . . . . . . . . . . . . . . . . . . . . . . . . .
86
7.4.1
Nucleoside analogues reverse transcriptase inhibitors
87
7.4.2
Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
87
7.4.3
Protease inhibitors
. . . . . . . . . . . . . . . . . . . .
87
7.4.4
Entry inhibitors . . . . . . . . . . . . . . . . . . . . . .
87
7.4.5
Limitations of antiretroviral therapies
. . . . . . . . .
88
7.3.1 7.4
81
84
7.1
HIV Post exposure prevention
79
. . . . . . . . . . . . . .
7 Prevention and treatment of Hiv/Aids
7.3
79
79
Types of FGM
blood products
78
. . . . . . .
HIV survival
77
Drug resistance
. . . . . . . . . . . . . . . .
88
Drug side eects
. . . . . . . . . . . . . . . .
89
Cost of treatment . . . . . . . . . . . . . . . .
89
7.4.6
Development of new HIV drugs and vaccine
7.4.7
Challenges in Developing AIDS Vaccines
7.4.8
7.4.9
.
. . . . . .
89
. . . . . . . .
90
Treatment of opportunistic infections . . . . . . . . . .
91
Support mechanisms . . . . . . . . . . . . . .
91
Steps involved in HIV testing in VCT . . . . . . . . . .
93
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Pretest counseling
Advantages of testing
. . . . . . . . . . . . .
93
Disadvantages . . . . . . . . . . . . . . . . . .
94
Post test counseling
. . . . . . . . . . . . . .
94
Role of VCT centers
. . . . . . . . . . . . . .
95
General reactions to testing HIV positive
. . . . . . . . . . . . . . .
. .
8 Concept of positive living
93
95
100
8.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . .
101
8.2
Home Based Care . . . . . . . . . . . . . . . . . . . . . . . . .
103
8.2.1
Rationale for Home Based care
104
8.2.2
Advantages of organized home based care
8.2.3
Components of home based care
8.2.4
Aspects of nutrition in comprehensive care of HIV/AIDS
8.3
. . . . . . . . . . . . .
104
. . . . . . . . . . . .
105
patients
. . . . . . . . . . . . . . . . . . . . . . . . . .
105
Advantages of good nutrition to PLWA . . . .
106
Principles of nutrition support for PLWA . . .
107
Management of pregnancy in HIV/AIDS 8.3.1
. . . . . . .
. . . . . . . . . . . .
108
Reducing the risk of transmission during pregnancy . .
108
Conception
109
The pregnancy
. . . . . . . . . . . . . . . . .
109
Delivery . . . . . . . . . . . . . . . . . . . . .
110
Breastfeeding . . . . . . . . . . . . . . . . . .
110
Testing babies for HIV . . . . . . . . . . . . .
110
. . . . . . . . . . . . . . . . . . .
9 Behavioral patterns and the spread of Hiv /Aids 9.1
Individual Behavioral Patterns and the spread of HIV /AIDS 9.1.1
9.1.2
. . . . . . . . . . . . . . . . . . . . . . .
115
Role of Gender in HIV/AIDS Transmission . . . . . . . . . . .
116
9.2.2
Safe sex and safer behaviors
115
. . . . . . . . . . . . . . .
9.2.1
9.3
114
Behaviour change could play a greater role in reducing HIV infection
9.2
113
Cultural, social, biological and economic pressures make women more vulnerable HIV that men. . . . . . . . . .
116
Remedy to above problem
117
. . . . . . . . . . . . . . . .
Drug/Alcohol Use and Abuse and the Spread of HIV/AIDS
.
118
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9.3.1
Relationship between drug use and HIV
. . . . . . . .
120
10 Implications of Hiv/Aids And International Responses to the Hiv/Aids Pandemic 123 10.1 To the individual 10.2 To the family
. . . . . . . . . . . . . . . . . . . . . . . . .
124
. . . . . . . . . . . . . . . . . . . . . . . . . . .
125
10.3 To the community
. . . . . . . . . . . . . . . . . . . . . . . .
125
10.3.1 How to solve negative eects . . . . . . . . . . . . . . .
126
10.4 Multi - Sectoral Impacts of HIV/AIDS
. . . . . . . . . . . . .
126
10.4.1 Impact on Industry and business sector . . . . . . . . .
126
10.4.2 Impact on agriculture . . . . . . . . . . . . . . . . . . .
126
10.4.3 Impact on education
127
. . . . . . . . . . . . . . . . . . .
10.4.4 Impact on health sector
. . . . . . . . . . . . . . . . .
10.4.5 Impact on economic growth
. . . . . . . . . . . . . . .
10.5 Responses of African Governments to HIV - AIDS epidemic
.
128 128 129
10.5.1 Formation of institution to coordinate and ght HIV pandemic
. . . . . . . . . . . . . . . . . . . . . . . . .
10.5.2 Declaring HIV a national disaster
. . . . . . . . . . .
129 129
10.5.3 Some of the strategies adopted by the Kenyan government to ght the spread of HIV/AIDS
. . . . . . . . .
129
Solutions to Exercises . . . . . . . . . . . . . . . . . . . . . . .
136
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SZL2111 HIV/AIDs
LESSON 1 General introduction Learning outcomes Upon completing this topic, a student should be able to:
De ne of terms related to HIV/AIDS
Understand the meaning of public health and its role in disease infection
Understand origins, theories and history of HIV/AIDS
Know various types of HIV
Global distribution and trends of HIV/AIDS
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1.1. Introduction HIV/AIDS is the worst pandemic the world has experienced in the last half of the 20th century. It has decimated whole population of people in certain region.
If one becomes infected with HIV, the virus begins to attach the
immune system. A person infected with HIV can look and feel perfectly well for many years and may not even know they are infected. Over a period of time, it is highly likely that HIV will damage the immune system and when this happens, one become vulnerable to illness often referred to as opportunistic infections that a healthy immune system would usually be able to ght o, and this leads to a condition known as AIDS - Acquired Immunode ciency Syndrome. AIDS is a collection of infections (usually severe) and cancers that may develop in people who are HIV positive. A person is said to have AIDS when they have developed one of these speci c illness, this is usually after a signi cant period of time often many years. Some people will receive an AIDS diagnosis when their T-cell count drops below 200 copies per cubic ml of blood. The eects that HIV infection may have on an individual vary dramatically. At one end of the spectrum a person may remain very well with virtually no ill eects. At the other end of the spectrum a person may have an AIDS diagnosis and develop a life threatening opportunistic infection. Currently there is no cure or vaccine for HIV/AIDS. Once a person contracts HIV, they will remain infected with the virus for life and are able to transmit the virus to others.
1.2. Justi cation of the course Education is an important component of preventing the spread of HIV. Aims of HIV/AIDS training,
To prevent new infections from taking place. i.e.
By giving people information about HIV - what HIV and AIDS are, how they are transmitted, and how people can protect themselves from infection.
Teaching people how to put this information to use and act on it practically for e.g. how to get and use condoms, how to suggest and practice safer sex, how to prevent infection in a medical environment or when injecting drugs.
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To improve quality of life for HIV positive people i.e. by -
Enabling and empowering them to improve their quality of life.
To be able to access medical services and drug provision
To be able to nd appropriate emotional and practical support and help
Teaching them about the importance of not passing on the virus
To reduce stigma and discrimination. - Discrimination against positive people can help the AIDS epidemic to spread
To help people focus upon the person than the disease and be more caring to the person.
To provide knowledge on modes of transmission especially to those affected and how to cope with the infected.
To initiate and sustain behavior changes necessary to reduce the rate of developing infections through safer sex practices.
1.2.1. Reasons for HIV/AIDS education/ why train in HIV/AIDS
HIV infection is lifelong and there is no cure
HIV is infectious, and those infected will remain infectious throughout their lives.
Fear arises from uncertainty of unpredictable medical conditions and reactions of people especially of those close to them.
Information and knowledge is incomplete about HIV care and prevention and at times even con icting.
The infected and aected are likely to have abroad of physical, psychological and social needs which may need adjustments e.g. nances.
Good management can contain some of these problems, early identi cation and intervention.
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It provides knowledge needed to initiate and sustain change in risky behavior.
It helps the infected nd a new or perhaps dierent approach to using safer sex and responsible social relationships.
It helps those who are infected to leave with the infection.
1.3. De nition of Terminologies Any specialized eld of study has some terms (jargons) that only professional in that eld comprehend clearly their meaning with reference to the subject. HIV/AIDS education is a subject that has borrowed heavily from medical sciences and therefore learners need to familiarize themselves with some terms that are commonly used in the subject 1. Rate - This is the amount of something in relation to something else shown as a proportion or percentage. Often it re ects the idea of speci c time. For example, imagine that 10,000 cases of AIDS have been reported to the ministry of health over the past ten years. You could tell someone this information alone, or you could say that the country only has a population of 100,000 people, and the rate of AIDS is 0.1, or 10% (10,000 cases divided by 100,000 people). 2. Incidence-This is how often new cases of a disease appear in a population during a set period of time, usually one year. For example, if you wanted to know the incidence of HIV in a village, you could test all the people in the village and record that information as your baseline. Then test all of the same people one year later. Count the number of people who did not have HIV during the rst test but did have the virus during the second test. Divide this number by the total number of uninfected people in the village. The result is the incidence of HIV in this village (the number of new infections per person per year). 3. Prevalence - This is the proportion of people who have a disease in a community at any one point in time. In the example above, the prevalence of HIV would be 10% the rst year (100 cases among 1,000 people
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living in the village) and 15% the second year (150 cases among 1,000 people living in the village). 4. Bias-This occurs when an unexpected factor aects the results of a study. For example, imagine you want to nd out how many pregnant women in your town have HIV. You test all the pregnant women who come to your medical clinic over a three-month period. Since people with HIV are more likely to be sick and come to the clinic, and you tested all pregnant women who came to the clinic, you will nd more women with HIV than if you tested every pregnant woman in the town. Testing only sick pregnant women in uenced your results. Your study was aected by bias. Bias can happen even when you are trying to avoid it. If you ask questions with a tone that tells people that you want them to answer in a certain way, you can bias your results.
For example, if you want
to know how many people inject drugs but ask, "You do not use those illegal, deadly drugs do you?" then fewer people will answer yes than really do use drugs. Your results will be biased. 5. Endemic- This term describes characteristic of a particular place or among a particular group or area of interest or activity. From disease point of view, the term is used to describe a disease occurring within a speci c area, region, or locale e.g. Malaria is endemic in a lot of Africa countries.
The term can also be used to describe a species of organ-
ism that is con ned to a particular geographical region, for example, an island or river basin. 6. Epidemic This is an outbreak of a disease that spreads more quickly and more extensively among a group of people than would normally be expected. Among the diseases that have occurred in epidemic proportions throughout history are bubonic plague, in uenza, smallpox, typhoid fever, tuberculosis, cholera, bacterial meningitis, and diphtheria. Occasionally, childhood diseases such as mumps and German measles become epidemics. 7. Epidemiology-This is the study of the incidence and distribution of diseases in large populations, and the conditions in uencing the spread
6
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and severity of disease.
For example in the study of the acquired im-
munode ciency syndrome (AIDS) epidemic in the early 1980s, both the National Cancer Institute (U.S.) and the Pasteur Institute (France) reported discovering that a retrovirus which came to be known as the human immunode ciency virus (HIV) was the main cause of the disease. 8. Pandemic a widespread epidemic that aects people in many dierent countries, across several continents e.g. HIV/AIDS
1.4. Public Health and Hygiene Public Health is the protection and improvement of the health of entire populations through community wide action, primarily by governmental agencies. Most people think of public health workers as physicians and nurses, but a wide variety of other professionals work in public health, including veterinarians, sanitary engineers, microbiologists, laboratory technicians, statisticians, economists, administrators, attorneys, industrial safety and hygiene specialists, psychologists, sociologists, and educators. Public health workers engage in activities outside the scope of ordinary medical practice and these include inspecting and licensing restaurants; conducting rodent and insect control programs; and checking the safety of housing, water, and food supplies etc. Hygiene is the science dealing with the preservation of health or the practice or principles of cleanliness. In the public domain, Public health o cers mainly manage this practice.
1.4.1. Public health programs may include:
• Vaccination This is the process of making the body resistant to a speci c disease by using a vaccine (a chemical that stimulates the body to create antibodies to ght a speci c infectious organism). Vaccination programs protect people against disease such as measles, mumps, diphtheria, and other childhood infectious diseases.
When small outbreaks of infectious disease threaten to grow into
epidemics, public health o cials may initiate new vaccination programs.
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• Rural and Urban Health Clinics Public health agencies operate local clinics that provide free or reduced-cost medical services to individuals, especially infants and children, pregnant and nursing women, people with drug abuse problems, physical disabilities, and other conditions. Public health clinics routinely screen patients for a number of infectious diseases and may provide free treatment if patients test positive. Each clinic tracks the incidence of certain communicable diseases in its area, and reports this information to national and international public health o ces.
• Disease Tracking and Epidemiology Threats to public health concerns change over time and epidemiologists and other o cials continuously evaluate epidemiological trends to determine how best to meet future public health needs.
Epidemiologists and other public
health o cials attempt to break the chain of disease transmission by notifying people who may be at risk for contracting an infectious disease. Public health o cials may also ensure that infected people complete treatment programs, so that the diseases are completely eliminated and the patients are no longer carriers of the infection.
• Sanitation and Pollution Control Disease-causing organisms are often transmitted through contaminated drinking water.
The single most eective way to limit water-borne diseases is to
ensure that drinking water is clean and not contaminated by sewage. Public health o cials establish sewage disposal and solid waste disposal systems, and regularly test water supplies to ensure they are safe. Public health programs establish and enforce laws for safe food storage and preparation;food-safety guidelines established by public health o cials.
• Medical Research Another component of public health is scienti c and medical research. Cadres of doctors and scientists work in laboratories to establish new ways to prevent, diagnose, treat, and cure disease and disability.
Scientists and doctors em-
ployed by the government conduct some biomedical research in public health facilities to nd better ways to protect human health.
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• Public Education Campaigns Many diseases are preventable through healthy living, and a primary public health goal is to educate the general public about how to prevent non-infectious diseases. Health promotion also encourages people to take advantage of early diagnostic tests that can make the outcome of disease more favourable e.g. early detection of breast cancer, for instance, increasing the chances of a cure. Detection and proper treatment of high blood pressure reduces the risk of a stroke, the leading cause of permanent disability in older people.
1.5. Types of HIV There are 2 main types of HIV:- HIV-1 &HIV-2. Both types are transmitted by sexual contact, through blood & from mother-to-child. They both appear to cause clinically indistinguishable AIDS. HIV-2 is less easily transmitted & the period between initial infection & illness is longer.
Its uncommon and
concentrated in West Africa countries, for example, Senegal, Ghana, Mali, Burkina Faso, Ivory Coast. Most HIV-2 reported in Brazil, Angola, Mozambique and Portugal can be traced back to West African contact. HIV-1 is the predominant virus world wide & generally when people refer to HIV without specifying the type they refer to HIV-1.
Example
.
HIV-1 subtypes
Group M (major) Group N (new) Group O (outlier) The 3 groups may represent separate introduction of Simian Immunode ciency Virus (SIV) into humans
Group O appears to be restricted to West-central Africa
Group N was discovered in 1998 in Cameroon & is extremely rare.
More than 90% of HIV-1 infections belong to group M
There are at least 9 subtypes within group M. They include A, B, C, D, F, G, H, J, and K.
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HIV1A found across west east axis from Ivory Coast to Djibouti via Kenya
HIV1B found in Thailand, Europe and S.America
HIV1C found in East Africa, Botswana and South Africa and is the commonest subtype globally accounting for 50%
HIV1D found in Congo, Kenya, Rwanda, Burundi, Tanzania and Uganda
HIV1E found in Thailand, Cameroon, Central African Republic and Congo
HIV1F found in Cameroon and Congo
HIV1G found in Congo and Gabon
HIV1H, J, K are rear but found in African continent.
In Kenya we have subtypes A, C, and D and this makes our country to be ranked amongst the leading countries with the highest HIV infections.
CRFs-circulating recombinant forms
- Occasionally two viruses of dier-
ent subtypes can meet in the cell of an infected person and mix together its genetic material to create a new hybrid virus in a process similar to sexual reproduction and sometime called viral sex. Many of these strains don't survive for long but those that infect more than one person are known as CRFs. E.g. CRF A/B is a mixture of subtype A&B.
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1.6. Origin, Theories and History of HIV/AIDS The origin of AIDS and HIV has puzzled scientists ever since the illness rst came to light in the early 1980s. For over twenty years it has been the subject of debate and the cause of countless arguments, with everything from a promiscuous ight attendant to a suspect vaccine program being blamed. The rst recognized cases of AIDS occurred in the USA in the early 1980s In 1981. The virus was discovered among homosexuals in the USA. A number of gay men in New York and San Francisco suddenly began to develop rare opportunistic infections and cancers that seemed stubbornly resistant to any treatment. They presented with a syndrome which included mouth rash, skin problems e.t.c. At this time, AIDS did not yet have a name, but it quickly became obvious that all the men were suering from a common syndrome. Their bodies' immunity was weakened and completely suppressed. Medics wrote their investigations in a journal. In 1983, it was discovered that the symptoms that were earlier observed were caused by a certain virus called immunode ciency virus and it was suppressing the immune system. In 1986, it became clear that the virus discovered in 1981 was spreading fast and many people suered from the same condition. In 1986, in West Africa, another virus was discovered & they called it immunode ciency virus type2. was made soon after.
The discovery of HIV, the Virus that causes AIDS
In Kenya, the 1st case was noted in 1983 in KNH &
it was noted that the body of the patient had low immunity. From 1981 to date the disease has claimed 22m lives & is still spreading. There is now clear evidence to prove that HIV does cause AIDS. So, in order to nd the source of AIDS, it is necessary to look for the origin of HIV, and nd out how, when and where HIV rst began to cause disease in humans. When and where the HIV virus rst emerged is probably going to remain a mystery for many years to come. While several theories have been put forward, there is no conclusive single agreement on the origin of HIV/AIDS. Some of the mostly acknowledged theories about the origin of HIV include:
Mysterious origins .
The tail of the comet theory
Religious theories (God's wrath and witch craft)
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Monkey origin theories
Conspiracy theories
The calculation theory
1.6.1. Mysterious origins This theory tries to account for the seemingly mysterious origin of HIV by locating it out of this world. It suggests that viral material was carried in the tail gases of a comet passing close to the earth and that this material was deposited, subsequently infecting nearby people. Although famous astronomer's names have been linked to this theory in the popular press, these scientists deny the possibility of this extraterrestrial phenomena and any personal connection to the theory.
1.6.2. Religious Theories (God's wrath and witch craft) Certain segments of the population have openly stated that their belief that AIDS is God's wrath since the Scriptures condemn the homosexual practice in which AIDS was rst observed in the Western world. If one adds to this belief the mysterious origin of the virus, and the apparently hopeless prospects for a cure, it will readily be understood how many have come to believe in Divine intervention, with AIDS being God's way of destroying sinners. If this were so, it would be di cult to see why God, after watching over thousands of years of vastly diering "sins', should suddenly decide to settle His score with homosexuals and drug addicts rather than any other 'sinners'.
The Bible
clearly speaks of a future (and imminent) judgment time when all sinners no matter what their speci c practice will have to pay the penalty for their sins. It does not tell, however, of a God who prejudges particular situations and who picks out special groups for early condemnation. Clearly, there are God-given laws which govern the harmonious interaction of body, mind and spirit. The origin of HIV/A1DS may be traced to an abuse of some of those laws pertaining to the physical and emotional or moral development of man and the presence of sin in the world. It should be recognized that once the process has started, 'guilty' and `innocent' suer alike nowhere is this more obvious or more poignant than in the AIDS pandemic. Rather than its being
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considered a visitation from God, many Africans believe that AIDS is caused by another supernatural power-witchcraft and they use anti-witchcraft rituals and objects to counteract the infection.
1.6.3. Monkey origin theories HIV is a lentivirus that attacks the immune system. Lentiviruses are in turn part of a larger group of viruses known as retroviruses. 'lentivirus' means 'slow virus' because they take such a long time to produce any adverse eects in the body and have been found in a number of dierent animals, including cats, sheep, horses and cattle. The lentivirus of interest in terms of the investigation into the origins of HIV is the Simian Immunode ciency Virus (SIV) that aects monkeys. It is generally thought that HIV is a descendant of a Simian Immunode ciency Virus because certain strains of SIVs bear a very close resemblance to HIV-1 and HIV-2, the two types of HIV For example, HIV-2 corresponds to SIVsm, a strain of the Simian Immunode ciency Virus found in the sooty mangabey (also known as the green monkey), which is indigenous to western Africa.
HIV-1, was until recently more di cult to place.
Until
1999, the closest counterpart that had been identi ed was SIVcpz, found in chimpanzees, but this virus still had certain signi cant dierences from HIV-1. Below are some of the most common theories about how this 'zoonosis' took place, and how SIV became HIV in humans. Zoonosis- viral transfer between animals & humans
• Hunter theory The most commonly accepted theory is that of the 'hunter'. In this scenario, SIVcpz was transferred to humans as a result of chimps being killed and eaten or their blood getting into cuts or wounds on the hunter. Normally the hunter's body would have fought o SIV, but on a few occasions it adapted itself within its new human host and become HIV-1. Discoveries such as this have lead to calls for an outright ban on bush meat hunting to prevent simian viruses being passed to humans.
• Oral Polio Vaccine (OPV) theory That HIV was transferred via medical experiments. That HIV could be traced to the testing of an oral polio vaccine called Chat, given to about a million peo-
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ple in the Belgian Congo, Ruanda and Urundi in the late 1950s. To be reproduced, live polio vaccine needs to be cultivated in living tissue, and Hooper's belief is that Chat was grown in kidney cells taken from local chimps infected with SIVcpz.
This, he claims, would have resulted in the contamination of
the vaccine with chimp SIV, and a large number of people subsequently becoming infected with HIV-1. However, in February 2000 the Wistar Institute in Philadelphia (one of the original places that developed the Chat vaccine) announced that it had discovered in its stores a phial of polio vaccine that had been used as part of the program. The vaccine was subsequently analysed and in April 2001 it was announced that no trace had been found of either HIV or chimpanzee SIV. A second analysis con rmed that only macaque monkey kidney cells, which cannot be infected with SIV or HIV, were used to make Chat. While this is just one phial of many, most have taken its existence to mean that the OPV vaccine theory is not possible. The fact that the OPV theory accounts for just one (group M) of several dierent groups of HIV also suggests that transferral must have happened in other ways too.
The nal
element that suggests that the OPV theory is not credible as the sole method of transmission is the argument that HIV existed in humans before the vaccine trials were ever carried out.
• The contaminated needle vaccine This is an extension of the original 'hunter' theory.
In the 1950s, the use
of disposable plastic syringes became commonplace around the world as a cheap, sterile way to administer medicines.
However, to African healthcare
professionals working on inoculation and other medical programmes, the huge quantities of syringes needed would have been very costly.
It is therefore
likely that one single syringe would have been used to inject multiple patients without any sterilisation in between.
This would rapidly have transferred
any viral particles (within a hunter's blood for example) from one person to another, creating huge potential for the virus to multiply in each new individual it entered, even if the SIV within the original person infected had not yet converted to HIV.
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• The colonialism theory The colonialism or 'Heart of Darkness' theory is one of the more recent theories to have entered into the debate. It is again based on the basic 'hunter' premise, but more thoroughly explains how this original infection could have lead to an epidemic.
During the late 19th and early 20 th century, much of Africa
was ruled by colonial forces. In areas such as French Equatorial Africa and the Belgian Congo, colonial rule was particularly harsh and many Africans were forced into labour camps where sanitation was poor, food was scare and physical demands were extreme. These factors alone would have been su cient to create poor health in anyone, so SIV could easily have in ltrated the labour force and taken advantage of their weakened immune systems to become HIV. A stray and perhaps sick chimpanzee with SIV would have made a welcome extra source of food for the workers.
Moore also believes that many of the
labourers would have been inoculated with unsterile needles against diseases such as smallpox (to keep them alive and working), and that many of the camps actively employed prostitutes to keep the workers happy, creating numerous possibilities for onward transmission.
1.6.4. The conspiracy theory Some say that HIV is a 'conspiracy theory' or that it is 'man-made'. A recent survey carried out in the US for example, identi ed a signi cant number of African Americans who believe HIV was manufactured as part of a biological warfare program, designed to wipe out large numbers of black and homosexual people. Many say this was done under the auspices of the US federal 'Special Cancer Virus Program' (SCVP), possibly with the help of the CIA. Some even believe that the virus was spread (either deliberately or inadvertently) to thousands of people all over the world through the smallpox inoculation program, or to gay men through Hepatitis B vaccine trials.
1.6.5. The calculated theory Opponents of the monkey theories argue that viral sequencing of HIV strains indicate that HIV has been around probably for hundreds of years.
This is
latest theory on the origin of HIV when a team of scientists using computer technology to study the structure of HIV calculated the rate at which the virus
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mutates for the HIV viral sub-bytes to have a common ancestor. This process revealed that HIV originated around 1930 in rural areas of Central Africa, where the virus may have been present for many years in isolated communities. The virus probably did not spread because members of these rural communities had limited contact with people from other areas. But in the 1960s and 1970s, political upheaval, wars, drought, and famine forced many people from these rural areas to migrate to cities to nd jobs. During this time, the incidence of sexually transmitted infections, including HIV infection, accelerated and quickly spread throughout Africa.
As world travel became more prevalent,
HIV infection developed into a worldwide epidemic. Studies of stored blood from the United States suggest that HIV infection was well established there by 1978. Rather than acquiring HIV from SIV it is thought that HIV mutated to become ever more infectious. We will probably never know exactly when and where the virus rst emerged, but what is clear is that sometime in the middle of the 20th century, HIV infection in humans develop and into the epidemic of disease around the world that we now refer to as AIDS.
Example Solution :
.
Describe the dierence Between HIV and AIDS?
HIV is the human immunode ciency virus that causes AIDS (ac-
quired immunode ciency syndrome).
When HIV infects someone, the virus
enters the body and begins to multiply and attack immune cells that normally protect us from disease. It's only when someone with HIV begins to infections and illnesses that they're diagnosed with AIDS.
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Learning Activities Read more papers and journal articles on current advances in HIV/AIDs research. Visit the reproductive health clinic/ section in a hospital around you and get to learn various methods used to control HIV/AIDs and other STIs. Exercise 1.
Revision Questions
Give an account of the limitations of Oral Polio Vaccine Theory as a possible explanation to the origin of HIV? Exercise 2.
Describe the dierence Between HIV and AIDS?
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Assignments 1. Comprehensively discuss the global distribution and trends of HIV/AIDs. Narrow down speci cally to Kenya and use current data and information. 2. Discuss myth associated with HIV/AIDs in your community.
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 2 Sex education and Human sexuality Learning outcomes By the end of this topic you should be able to;
To know what sex education entails
Describe the some of the common STIs
Understand the Myths surrounding sexuality
Understand the relationship between STIs and HIV
Role of sex education as HIV control and management strategy
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2.1. What is sex education? Sex education, also called sexuality education or sex and relationships education.
It's the process of acquiring information and forming attitudes and
beliefs about sex, sexual identity, relationships and intimacy. It is also about developing young people's skills so that they make informed choices about their behavior, and feel con dent and competent about acting on these choices. It is widely accepted that young people have a right to sex education, partly because it is a means by which they are helped to protect themselves against abuse, exploitation, unintended pregnancies, sexually transmitted diseases and HIV/AIDS.
2.1.1. Aims of sex education
To reduce the risks of potentially negative outcomes from sexual behavior like unwanted or unplanned pregnancies and infection with STDs
To enhance the quality of relationships.
To develop young people's ability to make decisions over their entire lifetime.
2.1.2. Myths surrounding sexuality Myths are commonly held believes that are untrue or without foundations. Myths are universal; occurring in almost all cultures and attempts to explain assorted topics on humanity, and may have both religious and non religious dimensions.
The concepts of sex being a necessary evil and the less said
about it the better have led to many misconceptions about sex. Most common sexual myths arise out of ignorance and these circulate more in adolescents and with lack of information they internalize this and practice and this may lead to exposure to HIV/AIDS.
2.2. Sexually Transmitted Diseases Sexually transmitted diseases (STD) are caused by communicable agents (viruses, bacteria, parasites etc) that are principally transmitted during sexual intercourse resulting in clinical illness. How, sometimes infection with these agents does not result in clinical disease but the agents can be transmitted from the
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host organism to their sexual partners. This has given rise to the term sexually transmitted infections (STI). Some persons are thus healthy carriers. There are at least 25 dierent sexually transmitted diseases. What they all have in common is that they can be spread by sexual contact, including vagina, anal and oral sex.
2.2.1. How do you know that you have an STD? Anyone who is sexually active can be at risk from STDs.
Some STDs can
have symptoms, such as genital discharge, pain when urinating and genital swelling and in ammation. Many STDs, such as Chlamydia, can frequently be symptom less. This is why it is advisable to have a sexual health checkup, to screen for STDs, if you think you have been at risk. It can sometimes take a long time for STDs to display any symptoms, and you can pass on any infections during this time, further demonstrating the need to be tested and treated. If you are in a relationship, and are diagnosed with an STD, it does not necessarily mean that your partner has been unfaithful. Symptoms of STDs can present themselves months after infection. Many STDs are very infectious and can cause long-term or permanent damage, including infertility if left untreated. Many STDs can be easily passed onto sexual partners, and some STDs can be passed from a mother to her unborn child too. STDs can also aid the transmission of HIV.
2.2.2. How STDs are transmitted STDs are transmitted by infectious agent microscopic bacteria, viruses, parasites, fungi, and single-celled organisms called protozoa - that thrive in warm, moist environments in the body, such as the genital area, mouth, and throat Most STDs are spread during sexual intercourse (vaginal or anal), but other forms of sexual contact, such as oral sex, can also spread disease. Some STDs are passed from an infected mother to her child before birth, when the infection crosses the placenta and enters the baby's bloodstream; during childbirth, as the baby passes through the birth canal; or after birth, when the baby consumes infected breast milk.
Some viral STDs, especially AIDS, may be
transmitted by blood. Such STDs may be passed between people who share infected needles or received through a transfusion of infected blood. Some peo-
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ple mistakenly believe that STDs can be transmitted through shaking hands or other casual contact, or through contact with inanimate objects such as clothing or toilet seats. Such transmissions are extremely rare.
• Factors that enhance chances of getting infected with STD 1. The potential for sexual activity is greatest from adolescence to the third decade: 15 years and older. The greatest risk occurs in the age group 18-35.
However, the trend is towards very early sexual debut, among
teenagers below 15 years of age, as society changes and liberal attitudes become the norm in formerly traditional societies . 2. Marital status and occupation aect exposure to STDs. Due to industrialization and consequent urbanization; there is usually a large group of single, poorly paid and unemployed young people who live in shanties in towns. Sexual intercourse, for pleasure and for gain, assumes an important role in such circumstances.
Prostitution and promiscuity ourish
under these conditions and so do STDs. Promiscuous sexual behaviour is closely associated with the acquisition and spread of STDs in any group of people.
There are certain factors that may reduce promiscuous be-
haviour in individuals. The more of these factors exist in an individual's life, the less the risk of STDs . 3. Ethnicity is not a risk factor for STDs, but it is closely associated with speci c cultural practices that may predispose to transmission of STDs. In some groups, certain celebrations and rituals (e.g., cleansing after the death of a family member) may involve high-risk sexual practices that predispose individuals to transmission of STIs, such as infection with human immunode ciency virus (HIV), the cause of acquired immunode ciency syndrome (AIDS). A surviving HIV-positive spouse may have to have sex with someone else as part of a ritual . Alternatively, "professional hired cleansers" may infect healthy widows and widowers. Many such funeral events are also associated with much promiscuity as celebrations are held over a week or so with men and women having many opportunities for casual sex. Conversely, societies with strict moral codes regarding sex and marriage have a much lower prevalence of STDs .
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2.2.3. Prevention and Control of STIs One can minimize the risk of getting infected with STIs by having protected sex with condoms and getting tested together with sexual partner(s).
The
more partners one has, the greater the risk of acquiring an STD. Other ways to reduce the risk include using dental dams and condoms during oral sex, clean sex toys after use, clean your hands after having sex, and improving genital hygiene routines.
• Importance of early diagnosis and treatment In many resource poor countries, the approach to diagnosis and treatment of STDs has changed radically in the last few years.
The emphasis is now on
recognition of groups of signs and symptoms, or syndromes, rather than strict etiologic diagnosis based on laboratory ndings as a basis for patient management. Syndromes are based on the clinical presentation of the commonest STDs in the particular country, or region within a country, and patients are treated for the likely STDs that commonly cause that particular combination of signs and symptoms. The commonest cause of urethral discharge in males in Africa, for example, is gonorrhea and Chlamydia urethritis, either individually or in combination. In the new approach, the patient is treated for both infections. Other causes are considered if there is no improvement (Adler, 1996., Holmes, 1990). The advantage of this approach is that even the lowest cadres in the health service can treat patients eectively with a minimum of retraining, without requiring the assistance of a laboratory. The main disadvantage is a certain amount of over-treatment for diseases that are not present, but this is a small price to pay for increased access to STD treatment services for the whole community.
2.2.4. Basic information on some common STDs 1. Bacterial Vaginosis - (BV) is not strictly an STD as it is not transmitted via sexual intercourse. However, it can be exacerbated by sex and is more frequently found in sexually active women than those who have never had intercourse. It is caused by an imbalance in the normal healthy bacteria found in the vagina and although it is relatively harmless and may pass unnoticed, it can sometimes produce an abundance of unpleasant shy
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smelling discharge. Whilst there is no clear explanation as to why BV occurs, there have been suggestions that the alkaline nature of semen could be one cause, as it may upset the acidic nature of the vaginal bacteria. Another cause can be the use of an intrauterine contraceptive device (coil). A woman cannot pass BV to a man, but it is important she receives treatment as BV can occasionally travel up into the uterus and fallopian tubes and cause a more serious infection. Treatment for BV consists of applying a cream to the vagina or taking antibiotics. 2. Balanitis - is often referred to as a symptom of infection, and not necessarily an infection in its own right. It is not strictly an STD, more a consequence of sexual activity. It only aects men and usually presents itself as an in ammation of the head of the penis, and is more common in men who are not circumcised. It can be caused through poor hygiene, irritation due to condoms and spermicides, using perfumed toiletries and by having thrush. It can be prevented through not using certain toiletries and by washing under the foreskin. Treatment can consist of creams to reduce in ammation and antibiotics if necessary. 3. Chlamydia - is the most common treatable bacterial STD. It can cause serious problems later in life if it is not treated. Chlamydia infects the cervix in women. The urethra, rectum and eyes can be infected in both sexes.
Symptoms of infection may show up at anytime.
is between 1 to 3 weeks after exposure.
Often this
However, symptoms may not
emerge until a long way down the line. 4. Crabs or Pubic Lice - are small, crab shaped parasites that live on hair and which draw blood. They live predominantly on pubic hair, but can also be found in hair in the armpits, on the body and even in facial hair such as eyebrows. They can live away from the body too, and therefore can be found in clothes, bedding and towels. You can have crabs and not know about it, but after 2 to 3 weeks, you would expect to experience some itching. Crabs are mainly passed on through body contact during sex, but they can also be passed on through sharing clothes, towels or bedding with someone who has them. There is no eective way to prevent yourself becoming infected, though you can prevent others becoming
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infected by washing clothes and bedding on a hot wash. Lotions can be bought from pharmacies and applied to the body to kill o the parasites. Shaving o pubic hair will not necessarily get rid of crabs. 5. Epididymitis - refers to in ammation of the epididymitis, a tube system above the testicles where sperm are stored. It is not always the result of an STD, but if it is, it is usually due to the presence of Chlamydia or Gonorrhoea. Symptoms will present themselves in the form of swollen and painful testicles and scrotum. The best way of preventing it is to use condoms during sex, as this is the most eective way to prevent Chlamydia and Gonorrhoea.
Epididymitis itself cannot be passed on,
though any other infections that may have caused epididymitis can be passed on (see Chlamydia and Gonorrhoea sections). Treatment usually involves treating the underlying infection with antibiotics. 6. Genital herpes - is caused by the herpes simplex virus. The virus can aect the mouth, the genital area, the skin around the anus and the ngers. Once the rst outbreak of herpes is over, the virus hides away in the nerve bres, where it remains totally undetected and causes no symptoms. Symptoms of the rst infection usually appear one to 26 days after exposure and last two to three weeks. Both men and women may have one or more symptoms, including an itching or tingling sensation in the genital or anal area, small uid- lled blisters that can burst and leave small sores which can be very painful, pain when passing urine, if it passes over any of the open sores and a u-like illness, backache, headache, swollen glands or fever. Find out more about genital herpes. 7. Genital warts - are small eshy growths which may appear anywhere on a man or woman's genital area. They are caused by a virus called the Human Papilloma Virus (HPV). Warts can grow on the genitals, or on dierent parts of the body, such as the hands. After you have been infected with the genital wart virus it usually takes between 1 and 3 months for warts to appear on your genitals. You or your partner may notice pinkish/white small lumps or larger cauli ower-shaped lumps on the genital area.
Warts can appear around the vulva, the penis, the
scrotum or the anus. They may occur singly or in groups. They may
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itch, but are usually painless. Often there are no other symptoms, and the warts may be di cult to see. If a woman has warts on her cervix, this may cause slight bleeding or, very rarely, an unusual coloured vaginal discharge. Find out more about genital warts. 8. Gonorrhoea - is a bacterial infection.
It is sexually transmitted and
can infect the cervix, urethra, rectum, anus and throat. Symptoms of infection may show up at anytime between 1 and 14 days after exposure. It is possible to be infected with gonorrhoea and have no symptoms. Men are far more likely to notice symptoms than women. 9. Gut Infections - can be passed on during sex. Two of the most common infections are Amoebiasis and Giardiasis. They are bacterial infections, and when they reach your gut they can cause diarrhoea and stomach pains. Gut infections can be passed on when having sex with someone who is infected, especially during activities that involve contact with faeces, such as rimming and anal sex. Infection can be prevented through using condoms, dental dams or latex gloves.
Sex toys should be thor-
oughly cleaned after use and hands washed after any contact with faeces. Anti-diarrhoea treatments should be enough to treat most infections, but antibiotics can also be used. 10. Hepatitis - causes the liver to become in amed. There are various different types of hepatitis, the most common being hepatitis A, B and C. Each of these viruses acts dierently. Hepatitis can be caused by alcohol and some drugs, but usually it is the result of a viral infection. Find out more about hepatitis. 11. Molluscum - is a skin disease caused by the Molluscum Contagiosum Virus. It appears as small bumps on the skin, and can last from a couple of weeks to a few years.
Molluscum cause small, pearl-shaped bumps
the size of a freckle on the thighs, buttocks, genitalia and sometimes the face. They are passed on through body contact during sex and through skin-to-skin contact. Transmission can be prevented by using condoms, by avoiding skin-to-skin contact with someone who is infected and by not having sex until they have been treated. In most cases molluscum
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do not need treatment and will disappear over time. However, they can be frozen o or a chemical can be painted on. 12. Non-Speci c Urethritis (NSU) - is an in ammation of a man's urethra. This in ammation can be caused by several dierent types of infection, the most common being Chlamydia. NSU may be experienced months or even in some cases years into a relationship. The symptoms of NSU may include pain or a burning sensation when passing urine, a white/cloudy uid from the tip of the penis that may be more noticeable rst thing in the morning, feeling that you need to pass urine frequently. Often there may be no symptoms, but this does not mean that you cannot pass the infection on to your partner(s). 13. Scabies - is caused by a parasitic mite that can get under the skin and cause itching. The mites are very small and cannot be seen, and many people do not now they have them.
They can cause itching, and this
can start between 2 to 6 weeks after infection.
Signs of infection can
be red lines under the skin of the hands, buttocks and genitals.
The
most common way of becoming infected is through body contact during sex, though it is also possible to be infected through sharing towels and clothes with someone who is infected. This route however is uncommon. There is no eective way to prevent yourself becoming infected, though you can prevent others becoming infected by washing clothes and bedding on a hot wash. Lotions can be bought from pharmacies and applied to the body to kill o the parasites. 14. Syphilis - is not a common infection in the UK but it is more common in some other countries. It is a bacterial infection. It is usually sexually transmitted, but may also be passed from an infected mother to her unborn child. The signs and symptoms of syphilis are the same in both men and women. They can be di cult to recognise and may take up to 3 months to show after having sexual contact with an infected person. Syphilis has several stages. The primary and secondary stages are very infectious. 15. Thrush, also known as Candidiasis - is yeast which lives on the skin and
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is normally kept in check by harmless bacteria. If this yeast multiplies however, it can cause itching, swelling, soreness and discharge in both men and women. Women may experience a thick white discharge and pain when passing urine.
Men may experience the same discharge in
the penis and di culty pulling back the foreskin. Thrush can be passed on when having sex with someone who is infected, but also if you wear too tight nylon or lycra clothes or if you are taking certain antibiotics. Sometimes the cause may be unclear however.
Transmission can be
prevented by using condoms during sex and by men washing underneath their foreskin.
Treatment for thrush involves taking or applying anti
fungal treatments. Thrush can reoccur, especially in women. 16. Trichomonas Vaginosis - also known as Trich is caused by a parasite that is found in women's vagina's and men's urethra's. Often there are not any symptoms.
If symptoms are present, they can include pain when
urinating and discharge in men and discharge, soreness when having sex and when urinating and in ammation of the vulva in women.
Trans-
mission normally occurs through having oral, anal or vaginal sex with an infected person.
Treatment consists of taking antibiotics, and the
infection should not reoccur. 17. AIDS - this is a fatal disease that, once symptoms and signs develop, causes death in less than 2 years (Porth 1998). The virus causing this disease is transmitted most commonly through unprotected sexual intercourse. There is no cure or vaccine, although onset of symptoms can be delayed by the use of antiretroviral drugs. Communities must be taught how to prevent AIDS by limiting sexual activity to one faithful partner. The male and female condoms are an eective method of preventing AIDS and other sexually transmitted diseases when used consistently for casual sexual contacts.
2.2.5. Relationship between HIV and Sexually transmitted infections
STDs enhances HIV transmission by causing open sores and skin injuries in sex organs through which the HIV enters.
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A lot of T-lymphocytes (cells found in the blood and in the lymphatic tissues that ght infections) are mobilized to ght the STD infections and since these are the targets of HIV, a lot of them are infected by HIV and destroyed and the patient goes down faster with the HIV.
The mode of transmission for the STDs is also the same as mode of transmission of HIV.
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Exercise 3.
Revision Questions
Explain any six sexuality myths that have lead to high risk sexual behaviors among youths in Kenya today
Example Solution :
.
Brie y describe the sexual transmission of HIV/AIDS
The risk of transmission through unprotected vaginal sex is thought
to be lower than anal sex, though still highly signi cant. However, where there is a risk of vaginal tears or sores e.g. in the presence of sexually transmitted infection, the risk of transmission is increased signi cantly. HIV transmission through oral sex is a much debated subjected. However, the virus is present in blood and semen, which means that in theory, this is a possible transmission route. There may be an increased risk if there is ejaculation, bleeding gums, lips, or in ammation caused by common throat infections. The sharing of sex toys also carries a risk of HIV transmission. If more than one person is going to use a vibrator or dildo, is essential that it is cleaned thoroughly between uses or covered with afresh condom before each use. .
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References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 3 The Immune system Learning outcomes Upon completing this topic, you should be able to :
Have an overview of the Human Immune system(IS)
Understand various types of immunity
Describe various stages of immune response
What is immunode ciency?
Various disorders and diseases associated with immune system
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3.1. Overview of the Immune System Immune system is a system of biological structures and processes within an organism that protects against diseases by identifying and killing pathogens and tumor cells. The immune system is made up of organs that are involved in ghting invasion by foreign bodies. They include;
3.1.1. The bone marrow The bone marrow is the production site of the white blood cells(WBC) involved in immunity WBC involved includes the B-lymphocytes (B cells) and the T lymphocytes (T cells). The B-lymphocytes mature in the bone marrow and then enter the circulation.
T lymphocytes move from the bone marrow to
the thymus, where they mature into several kinds of cells capable of dierent functions Lymphoid organs The Lymphoid tissues include the thymus gland, the spleen, the lymph nodes, the tonsils and adenoids, and similar tissues in the gastrointestinal, respiratory, and reproductive systems The lymph nodes are distributed throughout the body. They are connected by lymph channels and capillaries, which remove foreign material from the lymph before it enters the bloodstream.
The lymph nodes also serve as centers for immune cell
proliferation. The remaining lymphoid tissues, such as the tonsils and adenoids and other mucoid lymphatic tissues, contain immune cells that defend the body against microorganisms
3.1.2. Types of Immunity
• Innate/ Inborn/Natural/Non-speci c immunity; Present at birth Provide non-speci c immunity to any foreign invador regardless of invadors' composition. Operates under certain mechanisms or factors
Physical/mechanical barrier
Skin protects from entry of pathogens to our body
Respiratory tracts- the hairs /cilia along the tract leads to coughing & sneezing in presence of microorganism hence act as lters to clear the pathogens from upper respiratory tract.
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Biochemical factors Acidic gastric juices e.g.
Hydrochloric acid in the
stomach. Enzymes present in sweat, saliva and breast milk respond by destroying invading microorganisms. Blood protein factors e.g. interferons, compliments, acute phase proteins destroy by puncturing holes in the body.
Genetic - control People may become carriers but not sick
Cellular factors - WBCs participate both in natural & acquired immune responses. The cells ght invading foreign bodies by releasing cell mediators.
Other cells (non-granular) e.g.
phagocytic i.e. sponses.
monocytes & macrophages are
engulf, digest &kill microorganism In ammatory re-
The in ammatory response is a major function of the natu-
ral (nonspeci c) immune system elicited in response to tissue injury or invading organisms. Chemical mediators assist this response by: Minimizing blood loss Walling o the invading organism. Activating phagocytes and promoting formation of brous scar tissues. Regeneration of injured tissue.
• Acquired/ Adaptive / Speci c Immunity Immunologic responses are acquired during life.
Are not present at birth.
They develop as a result of immunization/vaccination. Also developed after contracting a disease i.e. weeks or months after exposure to the disease, the body produces an IR su cient to defend against re-infection. The two types of acquired immunity: active and passive. In active acquired immunity, the immunologic defenses are developed by the person's own body. This immunity generally lasts many years or even a lifetime. Passive acquired immunity is temporary immunity transmitted from another source that has developed immunity through previous disease or immunization.
For example, gamma-
globulin and antiserum, obtained from the blood plasma of people with acquired immunity, are used in emergencies to provide immunity to diseases when the risk for contracting a speci c disease is great and there is not enough time for a person to develop adequate active immunity. Both types of acquired immunity involve humoral and cellular (cell-mediated) immunologic responses. It's divided into 2 forms
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1. Humoral immunity (AMI) Involves antibodies produced by B cells The antibodies recognize & bind speci cally to foreign antigens & may cause one of the following: -Break/ splitdown the membrane of Ag (lysis) -Coat the Ag making it easier for phagocytosis (opsonization) -Neutralize activities of toxins/ virus/ bacteria (neutralization) -Direct killing of foreign Ag ( cytotoxicity / cell killing) -Clump parasites together (agglutination) 2. Cell mediated immunity (CMI) - Two most important T cell subtypes are involved in CMI T helper and T killer cells
• Cells of the Immune System 1. T-Cells T lymphocytes are divided into two major subsets that dier in functions and identity (functionally and phenotypically (identi ably) dierent).
(a) The T helper subset, (CD4+ T cell) - The main function is to augment or potentiate immune responses by the secretion of specialized factors that activate other WBCs to ght o infection.
They in-
teract with B cells or T killer cells & help them respond to foreign agents. T helper1-controls intracellular pathogens (CMI) (b) T helper2 - controls extra cellular pathogens (AMI) b)T killer/suppressor subset (CD8+ T cell). These cells are important in directly killing certain tumor cells, viral-infected cells and sometimes parasites. They directly bind to foreign agents, attack & kill those cells thus eliminating them from the body. The CD8+ T cells are also important in down-regulation of immune responses.
NB: Both types of T cells can be found throughout the body.
They often
depend on the secondary lymphoid organs (the lymph nodes and spleen) as sites where activation occurs, but they are also found in other tissues of the body, most conspicuously the liver, lung, blood, and intestinal and reproductive tracts. 2. Natural Killer Cells (NK) Are similar to the killer T cell subset (CD8+ T cells).
They directly kill certain tumors such as melanomas, lym-
phomas and viral-infected cells, most notably herpes and cytomegalovirus-
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infected cells. NK cells, unlike the CD8+ (killer) T cells, kill their targets without a prior sensitization. But kill more eectively when activated by T h cell. 3. B Cells The major function of B lymphocytes is the production of antibodies in response to foreign proteins of bacteria, viruses, and tumor cells. Antibodies are specialized proteins that speci cally recognize and bind to one particular protein that speci cally recognize and bind to one particular protein.
Antibody production and binding to a foreign
substance or antigen, is critical as a means of signaling other cells to engulf, kill or remove that substance from the body. 4. Granulocytes or Polymorphonuclear (PMN) Leukocytes -It is a group of WBCs.
Granulocytes are composed of three cell types identi ed as
neutrophils, eosinophils and basophils, based on their staining characteristics with certain dyes. These cells are important in the removal of bacteria and parasites from the body. They engulf these foreign bodies and degrade them using their powerful enzymes. (a) Neutrophils -a/c60% - complete dvpt in the BM -enter blood & remain incirculation for 10hours - leave thro capillary wall & enter connective tissue - after a day or 2 they enter the digestive tract or urinary tract & are swept out of the body by waters. (b) Eosinophils a/c 3% of circulating WBCs - help control allergic reactions & helminth infections (c) Basophils- a/c less than 1% - controls allergic reactions, in ammatory reactions, clotting process & fat metabolism 5. Macrophages They are often referred to as scavengers or antigenpresenting cells (APC). This is because they pick up and ingest foreign materials and present these antigens to other cells of the immune system such as T cells and B cells. This is one of the important rst steps in the initiation of an immune response. Stimulated macrophages exhibit increased levels of phagocytosis and are also secretory. Monocytes - they cross capillary wall, enter tissue & dierentiate to macrophages, - destroy bacteria, dead cells and other matters - Are CD4+
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6. Dendritic Cells Dendritic cells function as APCs.
In fact, they are
more e cient APCs than macrophages. These cells are usually found in the structural compartment of the lymphoid organs such as the thymus, lymph nodes and spleen. They are also found in the bloodstream and other tissues of the body. It is believed that they capture antigen or bring it to the lymphoid organs where an immune response is initiated. They are extremely hard to isolate. Recent nding is that dendritic cells bind high amount of HIV, and may be a reservoir of virus that is transmitted to CD4+ T cells during an activation event.
Cells that possess CD4
markers include:
T helper cells
Macrophages
Monocytes
Colon cells
Dendritic cells
Retinal cells
NB: HIV attaches to any CD4+ cell.
Immune response to invasion
When bacteria, viruses or other pathogens overcome the body's natural immunity and gain entry into the blood system, three speci c mechanism of acquired immunity are initiated. They include:
The phagocytic immune response
The humoral or antibody immune response
The cellular or cell mediated immune response
1.
Phagocytic immune response
The rst line of defense, the phagocytic immune response, involves the WBCs (granulocytes and macrophages), which have the ability to ingest foreign particles. These cells move to the point of attack, where they engulf and destroy the invading agents.
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2.
Humoral or Antibody immune response
The humoral response is characterized by production of antibodies by the B-lymphocytes in response to a speci c antigen. Although the B-lymphocyte is ultimately responsible for the production of antibodies, both the macrophages of natural immunity and the special T-cell lymphocytes of cellular immunity are involved in recognizing the foreign substance and in producing antibodies.
3.
Antigen recognition
The part of the invading or attacking organism that is responsible for stimulating antibody production is called an antigen (or an immunogen). For example, an antigen can be a small patch of proteins on the outer surface of the microorganism. A single bacterium, even a single large molecule, such as a toxin (diphtheria or tetanus toxin), may have several such antigens, or markers, on its surface, thus inducing the body to produce a number of dierent antibodies. Once produced, an antibody is released into the bloodstream and carried to the attacking organism. There it combines with the antigen, binding with it like an interlocking piece of a jigsaw puzzle .
3.1.3. Stages in an immune response
• Recognition stage
The immune system's ability to recognize antigens as foreign, or non-self, is the initiating event in any immune response ( g 2.2). The body must rst recognize invaders as foreign before it can react to them. The body accomplishes recognition using lymph nodes and lymphocytes for surveillance. Lymph nodes are widely distributed internally and externally near the body's surfaces. They continuously discharge small lymphocytes into the bloodstream. These lymphocytes patrol the tissues and vessels that drain the areas served by that node.
Lymphocytes are found in the lymph nodes and in the circulating blood. The volume of lymphocytes in the body is impressive. These lympho-
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cytes recirculate from the blood to lymph nodes and from the lymph nodes back into the bloodstream, in a never-ending series of patrols. Some circulating lymphocytes can survive for decades.
Some of these
small, hardy cells maintain their solitary circuits for the lifetime of the person.
The exact way in which circulating lymphocytes recognize antigens on foreign surfaces is not known; however, theorists think that recognition depends on speci c receptor sites on the surface of the lymphocytes. Macrophages play an important role in helping the circulating lymphocytes process the antigens.
When foreign materials enter the body, a
circulating lymphocyte comes into physical contact with the surfaces of these materials.
Upon contact, the lymphocyte, with the help of
macrophages, either removes the antigen from the surface or in some way picks up an imprint of its structure, which comes into play with subsequent re-exposure to the antigen.
In a streptococcal throat infection, for example, the streptococcal organism gains access to the mucous membranes of the throat. A circulating lymphocyte moving through the tissues of the neck comes in contact with the organism. The lymphocyte, familiar with the surface markers on the cells of its own body, recognizes the antigens on the microbe as dierent (non-self ) and the streptococcal organism as antigenic (foreign).
This
triggers the second stage of the immune responseproliferation.
• Proliferation stage
The circulating lymphocyte containing the antigenic message returns to the nearest lymph node.
Once in the node, the sensitized lympho-
cyte stimulates some of the resident dormant T and-lymphocytes to enlarge, divide, and proliferate. T lymphocytes dierentiate into cytotoxic (or killer) T cells, whereas-lymphocytes produce and release antibodies. Enlargement of the lymph nodes in the neck in conjunction with a sore throat is one example of the immune response.
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• Response stage
In the response stage, the changed lymphocytes function either in a humoral or a cellular fashion.
The production of antibodies by the-
lymphocytes in response to a speci c antigen begins the humoral response. Humoral refers to the fact that the antibodies are released into the bloodstream and so reside in the plasma ( uid fraction of the blood).
With the initial cellular response, the returning sensitized lymphocytes migrate to areas of the lymph node (other than those areas containing lymphocytes programmed to become plasma cells). Here, they stimulate the residing lymphocytes to become cells that will attack microbes directly rather than through the action of antibodies. These transformed lymphocytes are known as cytotoxic (killer) T cells. The T stands for thymus, signifying that during embryologic development of the immune system, these T lymphocytes spent time in the thymus of the developing fetus, where they were genetically programmed to become T lymphocytes rather than the antibody-producing-lymphocytes. Viral rather than bacterial antigens induce a cellular response.
This response is manifested
by the increasing number of T lymphocytes (lymphocytosis) seen in the blood smears of people with viral illnesses, such as infectious mononucleosis.
Most immune responses to antigens involve both humoral and cellular responses, although one usually predominates. For example, during transplantation rejection, the cellular response predominates, whereas in the bacterial pneumonias and sepsis, the humoral response plays the dominant protective role.
• Eector stage
In the eector stage, either the antibody of the humoral response or the cytotoxic (killer) T cell of the cellular response reaches and couples with the antigen on the surface of the foreign invader. The coupling initiates a series of events that in most instances results in the total destruction of the invading microbes or the complete neutralization of the toxin. The events involve interplay of antibodies (humoral immunity), complement, and action by the cytotoxic T cells (cellular immunity).
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Production of B-Lymphocytes
B-lymphocytes stored in the lymph nodes are subdivided into thousands of clones, each responsive to a single group of antigens having almost identical characteristics.
When the antigenic message is carried back
to the lymph node, speci c clones of the-lymphocyte are stimulated to enlarge, divide, proliferate, and dierentiate into plasma cells capable of producing speci c antibodies to the antigen. Other-lymphocytes differentiate into-lymphocyte clones with a memory for the antigen. These memory cells are responsible for the more exaggerated and rapid immune response in a person who is repeatedly exposed to the same antigen.
3.1.4. Role of antibodies in Humoral Immune Responses
Antibodies are large proteins called immunoglobulins because they are found in the globulin fraction of the plasma proteins.
Each antibody
molecule consists of two subunits, each of which contains a light and a heavy peptide chain. The sub-units are held together by a chemical link composed of disul de bonds. Each subunit has a portion that serves as a binding site for a speci c antigen referred to as the Fab fragment. This site provides the "lock" portion that is highly speci c for an antigen. An additional portion, known as the Fc fragment, allows the antibody molecule to take part in the complement system.
Antibodies defend against foreign invaders in several ways, and the type of defense employed depends on the structure and composition of both the antigen and the immunoglobulin. The antibody molecule has at least two combining sites, or Fab fragments. One antibody can act as a crosslink between two antigens, causing them to bind or clump together. This clumping eect, referred to as agglutination, helps clear the body of the invading organism by facilitating phagocytosis. Some antibodies assist in removing oending organisms through opsonization. In this process, the antigenantibody molecule is coated with a sticky substance that also facilitates phagocytosis.
Antibodies also promote the release of vasoactive substances, such as histamine and slow-reacting substance, two of the chemical mediators
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of the in ammatory response.
In addition, antibodies are involved in
activating the complement system.
3.1.5. Types of Immunoglobulins The body can produce ve dierent types of immunoglobulins. (Immunoglobulins are commonly designated by the abbreviation Ig.) Each of the ve types, or classes, is identi ed by a speci c letter of the alphabet (IgA, IgD, IgE, IgG, and IgM). Classi cation is based on the chemical structure and biologic role of the individual immunoglobulin.
The following list summarizes some out-
standing characteristics of the immunoglobulins:
IgG (75% of Total Immunoglobulin) (interstitial uid) tions
Appears in serum and tissues
Assumes major role in blood borne and tissue infec-
Activates complement system Enhances phagocytosis Crosses
placenta
IgA (15% of Total Immunoglobulin)
Appears in body uids (blood,
saliva, tears, breast milk, and pulmonary, gastrointestinal, prostatic, and vaginal secretions)
Protects against respiratory, gastrointestinal, and
genitourinary infections
Prevents absorption of antigens from food
Passes to neonate in breast milk for protection
IgM (10% of Total Immunoglobulin) serum
Activates complement system
IgD (0.2% of Total Immunoglobulin) serum
Appears mostly in intravascular
Appears as the rst immunoglobulin produced in response to
bacterial and viral infections
Appears in small amounts in
Possibly in uences B-lymphocyte dierentiation, but plays un-
clear role
IgE (0.004% of Total Immunoglobulin)
Appears in serum
in allergic and some hypersensitivity reactions
Takes part
Combats parasitic in-
fections
3.1.6. Cellular (or cell mediated) immune response
It is called cellular because it involves production of special cells T lymphocytes (or T cells) that are primarily responsible for cellular immu-
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Figure 3.1: Cellular (or cell mediated) immune response
nity. These lymphocytes spend time in the thymus, where they are programmed to become T cells rather than antibody-producinglymphocytes (Figure 2.3). Several types of T cells exist, each with designated roles in the defense against bacteria, viruses, fungi, parasites, and malignant cells. T cells attack foreign invaders directly rather than by producing antibodies.
Cellular reactions are initiated by the binding of an antigen with an antigen receptor located on the surface of a T cell. This may occur with or without the assistance of macrophages. The T cells then carry the antigenic message, or blueprint, to the lymph nodes, where the production of other T cells is stimulated. Some T cells remain in the lymph nodes and retain a memory for the antigen.
Other T cells migrate from the
lymph nodes into the general circulatory system and ultimately to the tissues, where they remain until they either come in contact with their respective antigens or die.
• Role of T lymphocytes Two major categories of eector T cells are helper T cells and cytotoxic T cells. These cells participate in destroying foreign organisms. Other T cells include suppressor T cells and memory T cells. T cells interact closely withcells, indicating that humoral and cellular immune responses are not separate,
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unrelated processes but rather branches of the immune response that can and do aect each other. 1. Helper T cells (helper CD4 cells) are activated upon recognition of antigens and stimulate the rest of the immune system.
When activated,
helper T cells secrete cytokines that attract and activate-cells, cytotoxic T cells, natural killer cells, macrophages, and other cells of the immune system (Laurence J. 1995).
Separate subpopulations of helper T cells
produce dierent types of cytokines and determine whether the immune response will be the production of antibodies or a cell-mediated immune response. Helper T cells produce lymphokines, one category of cytokines. These lymphokines activate other T cells (interleukin-2, or IL-2), natural and cytotoxic T cells (interferon-gamma), and other in ammatory cells (tumor necrosis factor).
Helper T2 cells produce IL-4 and IL-5, lym-
phokines that activate-cells to grow and dierentiate (Laurence J. 1995, Roit I; et al 1989)). 2. Cytotoxic T cells (killer T cells) attack the antigen directly by altering the cell membrane and causing cell lysis (disintegration) and releasing cytolytic enzymes and cytokines.
Lymphokines can recruit, activate,
and regulate other lymphocytes and WBCs. These cells then assist in destroying the invading organism. 3. Suppressor T cells, has the ability to decrease B-cell production, thereby keeping the immune response at a level that is compatible with health (e.g. su cient to ght infection adequately without attacking the body's healthy tissues). Memory T cells are responsible for recognizing antigens from previous exposure and mounting an immune response.
• Roles of null lymphocytes and natural killer cells in cellular immune responses Null lymphocytes and natural killer (NK) cells are other lymphocytes that assist in combating organisms. These are distinct from-cells and T cells and lack the usual characteristics of-cells and T cells. 1. Null lymphocytes, a subpopulation of lymphocytes, destroy antigens already coated with antibody. These cells have special Fc receptor sites on
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their surfaces that allow them to couple with the Fc end of antibodies (antibody-dependent, cell-mediated cytotoxicity, Beattie, T et al 2002). 2. Natural killer cells, another subpopulation of lymphocytes, defend against microorganisms and some types of malignant cells. NK cells are capable of directly killing invading organisms and producing cytokines. The helper T cells contribute to the dierentiation of null and NK cells (Laurence J. 1995).
3.1.7. Complement System
Circulating plasma proteins, which are made in the liver and activated when an antibody couples with its antigen, are known as complement. These proteins interact sequentially with one another in a cascade or "falling domino" eect. This complement cascade alters the cell membranes on which antigen and antibody complex form, permitting uid to enter the cell and leading eventually to cell lysis and death. In addition, activated complement molecules attract macrophages and granulocytes to areas of antigen antibody reactions. These cells continue the body's defense by devouring the antibody-coated microbes and by releasing bacterial agents.
Complement plays an important role in the immune response. Destruction of an invading or attacking organism or toxin is not achieved merely by the binding of the antibody and antigens; it also requires activation of complement, the arrival of killer T cells, or the attraction of macrophages.
3.2. Immunode ciency
When some or one of the components of the immune system is lacking, disorders or abnormalities arises and this is referred to as an immunode ciency. These abnormalities or disorders are either as a result of genetic abnormally (congenital) or are acquired within the course of life due to a number of factors
Old age
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Nutrition
Autoimmune disorder
Neoplastic disease
Chronic illness and surgery
Medication
Lifestyle and other factors
Stress
1. Age - People at the extremes of the lifespan are more likely to develop problems related to immune system functioning than are those in their middle years. Frequency and severity of infections are increased in elderly people, possibly from a decreased ability to respond adequately to invading organisms. Both the production and the function of T and B -lymphocytes may be impaired. The incidence of autoimmune diseases also increases with aging, possibly from a decreased ability of antibodies to dierentiate between self and non-self. Failure of the surveillance system to recognize mutant, or abnormal, cells may be responsible for the high incidence of cancer associated with increasing age. 2. Declining function of various organ systems associated with increasing age also contributes to impaired immunity. Decreased gastric secretions and motility allow normal intestinal ora to proliferate and produce infection, causing gastroenteritis and diarrhea.
Decreased renal circula-
tion, ltration, absorption, and excretion contribute to risk for urinary tract infections. Moreover, prostatic enlargement and neurogenic bladder can impede urine passage and subsequently bacterial clearance through the urinary system. Urinary stasis, common in elderly people, permits the growth of organisms. Exposure to tobacco and environmental toxins impairs pulmonary function.
Prolonged exposure to these agents
decreases the elasticity of lung tissue, the eectiveness of cilia, and the ability to cough eectively.
These impairments hinder the removal of
infectious organisms and toxins, increasing the elderly person's susceptibility to pulmonary infections and cancers.
Finally, with aging, the
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skin becomes thinner and less elastic.
Peripheral neuropathy and the
accompanying decreased sensation and circulation may lead to stasis ulcers, pressure ulcers, abrasions, and burns.
Impaired skin integrity
predisposes the aging person to infection from organisms that are part of normal skin ora. 3. Nutrition - Adequate nutrition is essential for optimal functioning of the immune system. Vitamin intake, essential for DNA and protein synthesis, if inadequate, may lead to protein-calorie de ciency and subsequently to impaired immune function.
Vitamins also help in the regulation of
cell proliferation and maturation of immune cells. Excess or de ciency of trace elements (i.e., copper, iron, manganese, selenium, or zinc) in the diet generally suppresses immune function.
Fatty acids are the build-
ing blocks that make up the structural components of cell membranes. Lipids are precursors of vitamins A, D, E, and K as well as cholesterol. Both excess and de ciency of fatty acids have been found to suppress immune function. 4. Depletion of protein reserves results in atrophy of lymphoid tissues, depression of antibody response, reduction in the number of circulating T cells, and impaired phagocytic function. infection is greatly increased.
As a result, susceptibility to
During periods of infection and serious
illness, nutritional requirements may be exaggerated further, potentially contributing to depletion of protein, fatty acid, vitamin, and trace elements and an even greater risk of impaired immune response and sepsis.
3.2.1. Autoimmune disorders In general, autoimmune disorders are more common in females than in males. This is believed to be the result of the activity of the sex hormones. The ability of sex hormones to modulate immunity has been well established. There is evidence that estrogen modulates the activity of T lymphocytes (especially suppressor cells), whereas androgens act to preserve IL-2 production and suppressor cell activity. The eects of sex hormones on B -cells are less pronounced. Estrogen activates the autoimmune-associated B-cell population that expresses the CD5 marker (an antigenic marker on the-cell). Estrogen tends to enhance
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immunity, whereas androgen tends to be immunosuppressive.Autoimmune disorders include lupus erythematosus, rheumatoid arthritis, or psoriasis
3.2.2. Neoplastic disease Immunosuppression contributes to the development of cancers; however, cancer itself is immunosuppressive.
Large tumors can release antigens into the
blood, and these antigens combine with circulating antibodies and prevent them from attacking the tumor cells. Furthermore, tumor cells may possess special blocking factors that coat tumor cells and prevent destruction by killer T lymphocytes. During the early development of tumors, the body may fail to recognize the tumor antigens as foreign and subsequently fail to initiate destruction of the malignant cells. Hematologic cancers, such as leukemia and lymphoma, are associated with altered production and function of WBCs and lymphocytes. All treatments that an individual has received or is currently receiving, such as radiation or chemotherapy, are vital. Radiation destroys lymphocytes and decreases the population of cells required to replace them. The size or extent of the irradiated area determines he extent of Immunosuppression. Whole-body irradiation may leave the patient totally immunosuppressed. Chemotherapy also destroys immune cells and causes Immunosuppression.
3.2.3. Chronic illness and surgery
Chronic illness may contribute to immune system impairments in various ways.
Renal failure is associated with a de ciency in circulating
lymphocytes. In addition, immune defenses may be altered by acidosis and uremic toxins. In diabetes, an increased incidence of infection has been associated with vascular insu ciency, neuropathy, and poor control of serum glucose levels. Recurrent respiratory tract infections are associated with chronic obstructive pulmonary disease as a result of altered inspiratory and expiratory function and ineective airway clearance. Additionally, surgical removal of the spleen, lymph nodes, or thymus or organ transplantation may place an individual at risk for impaired immune function.
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3.2.4. Special problems
Conditions such as burns and other forms of injury and infection may contribute to altered immune system function.
Major Burns or other
factors cause impaired skin integrity and compromise the body's rst line of defense. Loss of large amounts of serum with burn injuries depletes the body of essential proteins, including immunoglobulins. The physiologic and psychological stressors associated with surgery or injury stimulates cortisol release from the adrenal cortex; increased serum cortisol also contributes to suppression of normal immune responses.
1. Medications
In large doses, antibiotics, corticosteroids, cytotoxic agents, salicylates, nonsteroidal anti-in ammatory drugs, and anesthetics can cause immune suppression.
2. Lifestyle and Other Factors
Like any other body system, the immune system functions depend on the function of other body systems. Poor nutritional status, smoking, excessive consumption of alcohol and exposure to environmental radiation and pollutants have been associated with impaired immune function.
3.2.5. Role of immune system in HIV pathogenesis
The immune system is responsible for body defense against attack from pathogenesis
It is made up of white blood cells which include granulocytes such as neutrophils and basophils, and agranulocytes such as monocytes and lymphocytes.
T-helper lymphocytes have a CD4+ marker that the HIV use for entry into the cell and replicates
T-helper lymphocytes are important in immune regulation because when they are activated they recruit other immune cell involved in immune responses.
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HIV uses the CD4+ cells to replicate and produce more viral particles.
CD4 are killed and destroyed as viral production progresses
Cytotoxic T-lymphocytes with CD8+ marker target any virally infected CD4+ cells and kills them
Macrophages which have a CD4+ marker too act as reservoir and are also killed by cytotoxic
As virtually infected cells are killed by cytotoxic T-lymphocytes and more of the CD4+ cells destroyed as a result of viral replication, their numbers goes down.
The immune system is depleted of these crucial cells involved in body defense and becomes vulnerable to attack by opportunistic pathogens.
Example Solution :
.
Brie y describe the sexual transmission of HIV/AIDS
The risk of transmission through unprotected vaginal sex is thought
to be lower than anal sex, though still highly signi cant. However, where there is a risk of vaginal tears or sores e.g. in the presence of sexually transmitted infection, the risk of transmission is increased signi cantly. HIV transmission through oral sex is a much debated subjected. However, the virus is present in blood and semen, which means that in theory, this is a possible transmission route. There may be an increased risk if there is ejaculation, bleeding gums, lips, or in ammation caused by common throat infections. The sharing of sex toys also carries a risk of HIV transmission. If more than one person is going to use a vibrator or dildo, is essential that it is cleaned thoroughly between uses or covered with afresh condom before each use. .
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Exercise 4.
Revision Questions
Discuss the role of immune system in HIV pathogenesis
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References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 4 Biology of HIV Learning outcomes By the end of this topic you should be able to;
To know the nature of HIV
Describe the structure of HIV
Understand the Life cycle of HIV
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4.1. Nature of HIV HIV can't grow or reproduce on its own. It requires cell of living organisms to infect & reproduce. HIV is speci c to CD4+ cells in the human body i.e. cells with surface molecule called Cluster of Dierentiation 4. ing this molecule are called CD4+ cells.
Cells carry-
Therefore HIV cant survive in the
animal blood, because its only human blood that contains CD4+cells. HIV is a lentivirus.
Like all viruses in this group it attacks the immune system.
Lentiviruses are in turn part of a larger group of viruses called retroviruses. The term "retrovirus" stems from the fact that these kinds of viruses are capable of copying RNA into DNA. The name lentivirus means slow virus. This is because they take such a longtime to produce any adverse eects in the body.
4.2. The Structure of HIV Outside of a human cell, HIV exists as roughly spherical particles (sometimes called virions). The surface of each particle is studded with lots of little spikes. An HIV particle is around 100-150 billionths of a meter in diameter. That's about the same as 0.1 microns or 4 millionths of an inch or one seventieth of the diameter of a human CD4+ white blood cell.
Unlike most bacteria,
HIV particles are much too small to be seen through an ordinary microscope. However they can be seen clearly with an electron microscope.
NB: The proteins gp120 and gp41 together make up the spikes that project from HIV particles, while p17 forms the matrix and p24 forms the core. Structurally HIV consist of 1.
The viral envelope -
HIV has a diameter of 1/10,000 of a millimeter
and is spherical in shape.
The outer coat of the virus, known as the
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viral envelope, is composed of two layers of fatty molecules called lipids, taken from the membrane of a human cell when a newly formed virus particle buds from the cell. Embedded in the viral envelope are proteins from the host cell as well as 72 copies (on average) of a complex HIV protein (frequently called "spikes") that protrudes through the surface of the virus particle (virion).
This protein, known as Env, consists of
a cap made of three molecules called glycoprotein (gp) 120, and a stem consisting of three gp41 molecules that anchor the structure in the viral envelope.
Much of the research to develop a vaccine against HIV has
focused on these envelope proteins. 2.
Viral core/capsid - The viral core (or capsid) is usually bullet-shaped and is made from the protein P24. The core contains:
(a) Two copies of identical strands of RNA - HIVs' genetic material i. Almost all organisms, including most viruses, store their genetic material on long strands of DNA. ii. Retroviruses are the exception because their genes are composed of RNA (Ribonucleic Acid). iii. RNA has a very similar structure to DNA. However, small differences between the two molecules mean that HIV's replication process is a bit more complicated than that of most other viruses. (b) Three viral enzymes: required for HIV replication
Reverse transcriptase (RT)- converts viral RNA to ds DNA
Integrase- integrates DNA produced by RT into human DNA
Protease/proteinase- cuts proteins into segments & facilitates assemblance of new viral copies.
3.
Matrix - Just below the viral envelope is a layer called the matrix, which is made from the protein p17 which maintains the integrity of the virus structure & transport genetic material.
4.
Double layered lipid envelope 55
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HIV particles surround themselves with a coat of fatty material known as the viral envelope (or membrane).
Projecting from this are around 72 little spikes, which are formed from the proteins gp120 which protrudes from the surface & binds CD4+ cells and gp41. which is embedded within the envelope & is for entry/fusion.
4.3. The Life Cycle of HIV/ HIV Replication 1.
Attachment
- The gp120 on the surface of the virus particle bind to
the CD4 receptor on the surface of human T cell and the viral envelope fuses with the human T cell membrane. 2.
Entry - The contents of the HIV particle are then released into the cell, leaving the envelope behind.
3.
Reverse Transcription - Once inside the cell, the HIV enzyme reverse transciptase converts the viral RNA into DNA, which is compatible with human genetic material(DNA)
4.
Integration
- This DNA is transported to the cell's nucleus, where it
is spliced into the human DNA by the HIV enzyme integrase.
Once
integrated, the HIV DNA is known as provirus. 5.
Transcription - HIV provirus may lie dormant within a cell for a long time. But when the cell becomes activated, it treats HIV genes in the same way as human genes. First it converts them into messenger RNA (using human enzymes).
6.
Translation - Then the messenger RNA is transported outside the nucleus, and is used as a blueprint for producing new HIV proteins and enzymes.
7.
Assembly & Budding
- Among the strands of messenger RNA pro-
duced by the cell are complete copies of HIV genetic material.
These
gather together with newly made HIV proteins and enzymes to form new viral particles, which are then released from the cell. The enzyme
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protease plays a vital role at this stage of HIV's life cycle by chopping up long strands of protein into smaller pieces, which are used to construct mature viral cores. 8.
Maturation & release
- The newly matured HIV particles are ready
to infect another cell and begin the replication process all over again. In this way the virus quickly spreads through the human body. And once a person is infected, they can pass HIV on to others in their bodily uids.
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Exercise 5.
Revision Questions
Discuss the life cycle of HIV.
Example Solution :
.
Are there other ways to avoid getting HIV through sex?
The male condom is the only widely available barrier against sexual
transmission of HIV. Female condoms are fairly unpopular in the U.S. and still relatively expensive, but they are gaining acceptance in some developing countries. Eorts are also under way to develop topical creams or gels called "microbicides," which could be applied prior to sexual intercourse to kill HIV and prevent other STIs that facilitate HIV infection.
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Revision questions or guidelines 1. The knowledge of HIV life cycle has advanced the ght against HIV through designing of antiretroviral drugs. Using appropriate examples, discuss this statement. 2. Control of HIV/AIDs is directly linked to the knowledge of the transmission of the causative agent. Discuss in detail this statement. 3. The use of antiretroviral drugs is facing various challenges.
Highlight
and brie y discuss the major limitation to the use of ARVs. 4. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 5 Disease progression and symptoms Learning outcomes Upon completing this topic, you should be able to understand:
Stages of HIV infection
Factors that leads to faster progression fro HIV to full blown AIDs
Opportunistic infections
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5.1. Introduction HIV infects cells of the immune system and the central nervous system. The main cell HIV infects is T helper cell which is a crucial part of the immune system, because it co-ordinates the actions of other cells of the immune system. A large reduction in the number of T helper cells seriously weakens the immune system.
5.1.1. Exposure vs. Infection When HIV+ individual encounters an uninfected person, this does not always result in transmission of HIV to the uninfected person. Only a fraction of the exposed people will be infected. Dierent kinds of exposure between infected & uninfected individuals have dierent probabilities of leading to infection. Those who are exposed & become infected do not show sign of illnesses right away.
5.1.2. Infection vs. Disease Among individuals who become infected with HIV, not everybody will develop physical symptoms. Most viral infections don't show physical symptoms, but most people infected with HIV ultimately develop some disease symptoms. These disease symptoms are caused by damage or destruction of cells & tissues in the infected person.
In some cases the damage may result from direct
killing of cells by virus. In the case of AIDS, most of physical symptoms are the indirect result of damage to the immune system by HIV. Factors such as age, sex, genetic make-up, nutrition, environmental factors,& encounters with other infectious agents can in uence the exact nature of the symptoms in a particular individual.
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5.2. Stages of HIV Infection There are four stages of HIV infection and they include: 1. Primary H IV infection, window period & sero conversion 2. Clinically asymptomatic stage, 3. Symptomatic HIV infection, 4. Progression from HIV to AIDS.
5.2.1. Primary HIV infection This is the initial stage where one obtains the virus through the various modes of transmission. It can be divided into: 1.
Window period - This stage of infection lasts for a few weeks to about 3 months and is often accompanied by a short u-like illness or no signs. HIV cannot be detected in blood screening although HIV is present in blood & the blood in not 100% free of HIV. The virus cannot be seen in the rst 21 days. During this time a person can still transmit the virus to another person. It is the most crucial stage.
2.
Sero conversion
- This is the development of the anti-bodies.
Im-
mune system begins to respond to HIV by producing HIV antibodies and cytotoxic lymphocytes. If an HIV antibody test is done before seroconversion is complete then it may not be positive.
In this stage a
person may have u like illnesses, fever, fatigue, sore throat, joint pains & lymphadenopathy Some will not experience any illnesses at this stage.
5.2.2. Clinical asymptomatic HIV infection/ Latent phase The presence of HIV without major symptoms. Although there may be swollen glands.
The level of HIV in the peripheral blood drops to very low levels
but people remain infectious. HIV antibodies are detectable in the blood, so antibody tests will show a positive result.
HIV is not dormant during this
stage, but is very active in the lymph nodes. Large amounts of T helper cells are infected and die and a large amount of virus is produced. This period can last for many years (5 15 years)
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• Initial Infection Symptoms include:
Mononucleosis-like illness (sore throat, swollen glands, fever) & skin rash
Encephalopathy i.e. Brain infections - brain swelling & in ammation of the brain lining or meninges
This causes headache, fever, brain functions impairment, di culty in concentration, remembering or solving problems
Personality changes may also occur
NB: Asymptomatic period some type of balance exist between HIV infection & the immune system in the infected person
5.2.3. Symptomatic HIV infection/AIDS Related Complex (ARC) phase Over time the immune system loses the struggle to contain HIV due to the following main reasons: 1. The lymph nodes and tissues become damaged or 'burnt-out' because of the years of activity; 2. HIV mutates and becomes more pathogenic, i.e.
stronger and more
varied, leading to more T helper cell destruction; 3. The body fails to keep up with replacing the T helper cells that are lost. As the immune system fails, so symptoms develop. Initially many of the symptoms are mild, but as the immune system deteriorates the symptoms worsen. When the viral load reaches a critical amounts, the immune system is suppressed to such a degree that other infections which under normal circumstances will not be di cult to resist gain entrance i.e. opportunistic infections. Opportunistic infections they take advantage of the impairment of the immune system & sometimes are caused by organisms that don't cause infections/ diseases in man. Symptoms of HIV infection in this stage.
Two or more of the following signs /
symptoms may occur:
Chronic fever
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Lethargy (fatigue/ tiredness)
Continuous diarrhea - Eczema (allergy of the face)
More than 10% weight loss - Psoriasis (itchy pimples)
Lymphadenopathy
Dermatitis (itchy skin)
Night sweats
Oral candidiasis (sores in mouth)
Dementia (short term memory loss)
Incubation period
- is the length in time between initial infection &
becoming symptomatic. It varies between people & depends on a length of factors
5.2.4. Progression of HIV to AIDS As the immune system becomes more and more damaged the illnesses that present become more and more severe leading eventually to an AIDS diagnosis. It's the most advanced stage of HIV infection.
At this time when CD4 cell
count has gone down below 200 CD4 cells/ml, HIV develops to one or more severe opportunistic infections or cancer. The infection / cancer may be life threatening due to the weakened immune system.
Common symptoms in this stage/ Initial Disease Symptoms An infected individual may have symptoms from more than one of these classes; 1. HIV wasting syndrome:
- Sudden unexplained loss in body weight (
>10% of total body weight), unexplained chronic diarrhea (>1 month), Chronic weakness, unexplained prolonged fever usually at night that causes night sweats (>1 month) and brain damage due to high temp that causes fevers 2. Lymphadenopathy syndrome (LAS)/ persistent generalized lymphadenopathy (PGL): Lymph glands enlargement is persistent. They swell in groin, armpits, head & neck but are not painful. Some infected people may experience both LAS & Wasting Syndrome
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3. Neurologic disease - direct damage of the brain by HIV or by other agent. Damage of parts of the nervous system can also cause dierent neurologic symptoms. For example:
(a) Dementias - Impaired mental functions, forgetfulness, loss of mental functions. Di culty reasoning & performing mental tasks. Depression, social withdrawals & personality changes. Unable to care for themselves eventually. Coma & death may follow. (b) Spinal cord damage/ swelling (myelopathy) - Spinal cord transmits nerve impulses to the muscles of the body. Because of this, damage may result in weaknesses or paralysis of voluntary muscles/ limbs. (c) Peripheral nerve swelling/ damage (neuropathy) - these nerves sense pain. When damaged can cause burning or stinging sensations in the hands or feet or occurrence of numbness
NB:
individual patients may experience a mixture of any of these ill-
nesses Others include:
Coughs & gasping of breath, Seizure- lack of
coordination, Di culty or pain during swallowing, Psychotic symptoms - mental confusion & forgetfulness, Loss of vision, Severe headache, Nausea, Abdominal crump & vomiting, Extreme fatigue, Cancers-m of blood, and Coma. HIV+ patient can die any moment at this stage.
5.2.5. Other Complications in HIV Patients This manifest when immune system is weak and they include:
a)
Common brain infections - Tumors, Swelling of the brain, Nerve damage. They can cause Headache & confusion, Poor coordination of feet, Blindness, Enlarged lymph nodes, Fever, sore throat, weaknesses
b)
Common skin infections - When immune system is damaged in HIV patients the skin conditions tend to persist more & they become di cult to treat. In most cases these conditions are caused by bacteria, viruses or fungi.
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5.2.6. Factors that lead to faster development of HIV infection to full- blown AIDs 1.
Age - Persons who get infected after the age of 35years move faster from HIV infection to full blown AIDS than those who get infected in their mid 20s. Children who get infected at birth die faster simply because their immune system is not well developed at their tender age.
2.
Type of HIV contracted
- There are two well known types: HIV1
and HIV2. HIV1 is harsher on people hence kills faster than HIV2. 3.
Mode of transmission - HIV got through blood transfusion kills faster than one got through sexual contact. This is because the amount of virus channeled into the bloodstream is in large quantity.
4.
Ill - health & other types of infections
- People who are already
sick & then get infected move faster than those infected when healthy. Tropical diseases such as malaria, typhoid & intestinal worms makes patients to develop AIDS faster 5.
Nutritional status
- Those infected & are not eating enough of well-
balanced foods are more likely to develop AIDS faster 6.
Lifestyle
- People who expose themselves to re-infection with other
strains of HIV or STIs / STDs and other illnesses move faster from HIV to AIDS 7.
Opportunistic infections
- If they are not competently treated, then
the HIV+ person develops AIDS faster.
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5.3. Opportunistic Infections 1. Examples of fungal infections
(a) PCP - In ammation of the lungs caused by infection with fungus called Pneumocystis carinii. In amed areas of lungs appear as white spots in x-rays. It's the leading cause of death in AIDS patients i.e. about 50% of AIDS patients will eventually develop PCP (b) Candida - Fungus is similar to baker's yeast. & mucosal surfaces (mouth, vagina). white plaques that feel furry.
It is found on skin
In mouth they appear like
Antifungal e.g.
mycostatin can be
used. They are di cult to completely eliminate. They can spread to oesophagus & cause painful burning sensation when eating i.e. oesophagitis. 50% of AIDS patients will experience candidacies. (c) Systemic mycosis - Soil fungus that can cause generalized infections in AIDS patients. Exist in either mold like or yeast like form & are called dimorphic.
There are of 3 types - Histoplasmosis, Coccid-
iomycosis, & Cryptococcus. They cause lung infections in healthy patients. In AIDS patients, the brain, skin, bone, liver & lymphatic tissue may also be highly infected.
2. Example of Bacterial infections - Components of I.S. responsible for controlling the common bacteria are less aected by HIV infection, thus adult AIDS patients do not generally suer infections with common bacteria
(a) Mycobacterium - Infection with Mycobacterium avium intracellular is most common in AIDS patients.
It does not cause disease in
healthy people but it causes TB-like disease in the lungs of AIDS patients.
Also causes infection of BM & presence of bacteria in
blood at high levels. Patients will have fevers & low no. of white blood cells.
Mycobacterium tuberculosis that causes TB is also
common in AIDS patients.
3. Example of Viral infections
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(a) Cytomegalovirus (CMV) - Common virus that infect people inn childhood with no symptoms but may cause mononucleosis-like illness (sore throat, swollen glands, fevers) in adults. Congenital infections(fetus) can also lead to permanent brain damage. In AIDS patients CMV infect retinas of the eyes causing blindness & also adrenal glands leading to hormonal imbalance.
CMV can cause
pneumonia, fevers, rash & gastroenteritis in AIDS patients. CMV pneumonia in patients with PCP is fatal (b) Varicella (shingles) - Painful rash condition that occurs on human trunk. Latent varicella zoster (that causes chicken pox in childhood) is reactivated when the I.S. is compromised.
Antiviral drugs e.g.
acyclovir is sometimes used to control shingles
4. Example of Protozoan infections:
(a) Cryptosporidium gastroenteritis - It is caused by protozoan called cryptosporidium.
It infect lining of the intestinal tract & causes
diarrhea (gastroenteritis). In normal/ healthy people diarrhea lasts a few days but in AIDS patients it is prolonged & severe.
That
is about 20-50 watery stools per day accompanied by abdominal cramps & weight loss (b) Toxoplasmosis - It is caused by Toxoplasma gondii that causes asymptomatic infections in healthy adults.
In AIDS patients it
causes brain infections with symptoms similar to brain tumors (e.g. convulsions, dementias).
5. Examples of Cancers:
(a) Kaposi's sarcoma (KS) - Are tumors of blood vessels.
In non -
AIDS patients KS is seen in older men of Jewish ancestry. Initially few tumors appear as pink, purple or brown skin lesions located on arms or legs. Eventually they spread & become widely distributed in most linings of the body.
They are di cult to control if they
spread to the lungs. Chemotherapy can eradicate them.
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(b) Lymphomas - Cancers derived from B cells of immune system are the common type of lymphomas in AIDS patients.
Epstein-Barr
virus causes mononucleosis but it can also transform normal B cell into cancer cell. Unusual lymphoma that spread to the brain also occur in AIDS patients. (c) Cervical cancers - Its common in female AIDS patients. Infections with certain strains of Human Papilloma Virus (HPV) that cause warts in the genital tract is an underlying cause of cervical cancer. Cancer caused or induced by HPV develops faster when immune system is compromised in AIDS patients. (d) Hairy leukoplakia - Abnormal condition of the mouth in which white plaques appear on the surface of the tongue. This is due to abnormal growth of papillae cells of the tongue. They can't be scrapped o. They resemble cancer cells.
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Exercise 6.
Revision Questions
The progressions of HIV to AIDs involve dierent stages of clinical developments. Discuss
Example
.
Factors that lead to faster development of HIV infection to full
- blown AIDS
Solution :
Age - Persons who get infected after the age of 35years move faster
from HIV infection to full blown AIDS than those who get infected in their mid 20s. Children who get infected at birth die faster simply because their immune system is not well developed at their tender age. Type of HIV contracted There are two well known types: HIV1 and HIV2. HIV1 is harsher on people hence kills faster than HIV2. Mode of transmission - HIV got through blood transfusion kills faster than one got through sexual contact. This is because the amount of virus channeled into the bloodstream is in large quantity. Ill - health & other types of infections - People who are already sick & then get infected move faster than those infected when healthy - Tropical diseases such as malaria, typhoid & intestinal worms makes patients to develop AIDS faster Nutritional status - Those infected & are not eating enough of will balanced foods are more likely to develop AIDS faster. Lifestyle - People who expose themselves to re-infection with other strains of HIV or STIs/STDs and other illnesses move faster from HIV to AIDS. Opportunistic infections - If they are not competently treated, then the HIV+ person develops AIDS faster.
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References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 6 Transmission and diagnosis of HIV Learning outcomes Upon completing this topic, you should be able to understand:
Various methods used in diagnosis of HIV
The modes of HIV transmission
Pregnancy and HIV/AIDS
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6.1. Transmission of HIV
HIV is present in semen, vaginal/ cervical secretions & body uids. It may be present in tears, urine, csf, breast milk &infected discharges, saliva.
HIV is spread when an infected individual come into contact
with infected body uids or cells. How HIV is NOT transmitted.
There is no evidence to show that HIV can be transmitted by:
casual social contact e.g. shaking hands, hugging
sneezing or coughing
shared facilities & equipment e.g. toilets, swimming pools
non wet kissing
sharing food & utensils
insect bites e.g. mosquitoes - HIV only lives for a short time and does not reproduce in an insect
Injecting with sterile needles
Protected sex - If an unbroken latex condom is used, there is no risk of HIV transmission. There are myths saying that 'some very small viruses can pass through latex' - this is not true.
6.1.1. Modes of HIV Transmission 1.
Sexual contact - Any unprotected (no condom) penetrative sex whether vaginal, anal or oral can transmit HIV from infected individual to uninfected sexual partner.
(a) Heterosexual contact (man &woman) a/c 70%-80% of all HIV transmission. (b) Homosexual contact a/c 5-10% (c) Oral sex is low risk but oral ulcers, bleeding gums, genital sores & presence of STIs (gonorrhea, syphilis & genital ulcers) do increase the risk of hiv transmission
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(d) Rape, & sodomy victims could get infected if the attacker is HIV+. The victims should seek prompt medical attn because early treatment with ARVs can greatly reduce chances of HIV infection. They will also require specialized counseling & psychological /psychiatric care Factors that in uence transmission through sexual contact (e) The risk of HIV transmission through sexual contact is in uenced by a number of factors: i. level of virus in the body ii. number of sexual partners iii. sex male/female iv. age v. STDs/STIs vi. Condom use 2.
Intravenous Drug Use/ Contaminated Piercing Instruments
-
I.V. drug use is the administration of drugs of addiction e.g heroin into the blood stream by injecting into the veins. Most drug users tend to shoot in groups & often share needles. It therefore becomes very easy for transmission /infection to occur from one infected group member to another. It's a signi cant modes in the developed countries accounting for 5-10% of HIV infections. Procedures such as ear piercing & circumcisions when done with poorly cleaned & unsterile instruments can lead to HIV transmission. 3.
Occupational exposure/ Infection in the health-care setting
-
Occupational exposure is the accidental exposure of healthcare workers (e.g doctors &nurses) to body uids from an infected patient in their care. This is most frequently due to needle pricks or cuts with surgical instruments. Infection can also occur due to contact with infected blood, laboratory samples especially through broken skin. 4.
Mother - to - child transmission (MTCT)
- Also called Vertical
/ perinatal transmission & it accounts for 13-40% HIV infections. It's possible for HIV to be transmitted from HIV+ mothers to unborn child. This occurs in 3 ways:
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(a) During pregnancy- The virus crosses from mother's blood to child through the placenta. Although there's no exchange of blood between mother & child, researchers believe that the foetus can get HIV through the placenta i.e through diusion.
It accounts for
about 35% HIV infections (b) During birth Through exposure to mother's blood & other secretions. It accounts for 65% HIV infections (c) After birth- through breast feeding. Breast milk contains minimal quantities of HIV. It accounts for 15% HIV infections.
6.1.2. Factors that increase chances of MTCT/ Determinants
high level of HIV in mother's blood & other body uids (maternal viral load)
duration of exposure to maternal secretions during delivery
inadequate nutrition
pre-term delivery- premature babies are more prone to infection because the immune mechanism is still very weak/ immature
Maternal immune response- maternal CD4 cell count
prolonged membrane rupture-increased risk if more than 4hours
obstetrical procedures- e.g. vacuum assisted delivery
unprotected sexual intercourse
presence & amount of virus in the genital tract
Placenta barrier- breaches in barrier leads to mixing of maternal and foetal cells
Presence and amount of HIV in genital tracts
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6.1.3. Prevention of MTCT (PMTCT)
Prevent HIV infection in women i.e. encouraging teenage girls to delay sexual relationships & discordant couples to use of condoms.
Reduce the number of HIV exposed pregnancies i.e.
Women who are
HIV infected can use family planning methods to prevent pregnancies.
ART- to infected pregnant women.e.g. AZT (zidovudine/ azidothymidineNov `94) is taken in the last week of pregnancy and nevirapine is given at the onset of labour & to the HIV exposed babies within 3 days after birth
Preventing malaria - A woman who is infected with both HIV and malaria has an increased chance of passing HIV to her baby.
Anti-
malarial drug treatment during pregnancy is therefore an important part of preventing MTCT
Reducing trauma and shortening exposure of the baby to the virus during labour and delivery i.e. Modi ed obstetrical practices which include
make sure that the mother gives birth within 4 hours after membrane ruptures (water breaks),
avoid routine episiotomy,
avoid prolonged labour,
minimum use of vacuum or forceps delivery, and
Electing to use caesarian section.
Appropriate choice of feeding infants i.e. breastfeeding exclusively without any supplements followed by abrupt but timely weaning or replacement feeding from birth without any breast milk.
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6.2. Diagnosis of HIV and AIDs A number of tests are used to con rm the presence of antibody to HIV and to assist in diagnosing HIV infection.
6.2.1. The Enzyme-Linked Immunosorbent Assay (ELISA)
The test identi es antibodies directed speci cally against HIV. The ELISA test does not establish a diagnosis of AIDS. Rather, it indicates that the person has been exposed to or infected with HIV. People whose blood contains antibodies for HIV are said to be seropositive. HIV antibodies do not reach detectable levels in the blood for one to three months. This period is known as sero conversion during which antibody production to viral proteins take place. Window period is the time during which antibody detection using Elisa is negative.
In some cases it may take
even 6 months for the antibody levels to get high enough for detection.
6.2.2. The Western blot assay
It is another test that can identify HIV antigens and is used to con rm seropositivity as identi ed by the ELISA. This is a method that detects very low antigen levels such that one may test HIV negative by ELISA but test positive through western blot. Babies born of HIV mother have antibodies to HIV that were passed on during pregnancy through the placenta.
However these antibodies diminish with time such that by
15 months the child may test negative. Use of Western, blot con rms presence of HIV antigen and this rules out whether babies are positive because of HIV itself or because of maternal antibodies.
6.2.3. PCR
It is also used to detect HIV in high-risk seronegative people before the development of antibodies, to con rm a positive ELISA, to screen neonates, and to determine the exact strain of virus that is present.
6.2.4. CD4+Cell count
Once a patient is diagnosed positive the extent of damage to the immune system is determined by CD4+ cell count (T-helper cell count).
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The number of CD4 cells present is a direct indicator of the immune system's ability to ght o opportunistic infections. The test to measure CD4 cells requires a sample of blood to be taken and measurement is made of the number of CD4 cells in a cubic milliliter of blood and will give a picture of the health of the immune system-whether it is improving or declining. The CD4 count of a person who is not infected with HIV may lie anywhere between 500 and 1200.A drop in an HIV positive persons CD4 count usually occurs over a number of years. A CD4 count between 500 and 200 indicate that some damage to the immune system has occurred and a count below 350 or rapid decline is an indication that one should consider anti-HIV treatment.
6.2.5. Measuring viral load
Measuring viral load is essential to determine how active the viral replication is if one is taking anti-HIV medication, then it is also a direct indicator of how successful it is in suppressing viral replication.
The
viral load test requires the collection of a blood sample and estimates the number of HIV particles in the sample by looking for HIV genes. The level of viral load is generally seen as a good indicator of whether to start ant-HIV treatment. An undetectable viral load is an indication that both the risk of developing AIDS and the risk of developing drug resistance has been reduced. A high viral load is an indication of high levels of HIV in body uids while undetectable viral load indicates a reduction in levels of HIV in these uids but the risk of transmitting the virus is still present
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6.3. STIs, STDs, FGM and HIV/AIDS STDs are diseases that are transmittable from an infected person to another through sexual intercourse. STIs is a term applied to infections that are transmitted primarily through sexual contact be it vaginal, oral, or anal intercourse. They don't necessarily involve sexual activity but the organisms that cause STIs enters mostly through the soft & thin skin that cover the inner surfaces i.e.
mucus membrane of the vagina, urethra, anus & mouth.
However, in
some instances exposure to sores or other types of skin to skin contact may be insu cient to transmit the infection.
6.3.1. Common examples of STIs/ STDs
Syphilis
Gonorrhea
Candidacies
Hepatitis B & C.
Chancroids ( genital sores)
Genital herpes (Herpes Simplex V)
Genital warts( Human Papilloma V)
Bacterial vaginosis.
Trichomoniasis
6.3.2. Relationship between HIV & STDs/STIs STIs/STDs increase the risk of HIV infection by mobilizing a high population of T cells to ght the STI/STD. Since the T cells are the target cells for attack by HIV, such a large population will inevitably provide breeding ground for HIV. STDs/STIs also increase the risk of acquiring or transmitting the virus. Both are transmitted through sexual contact & to unborn baby during pregnancy or at birth.
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6.3.3. Dangers/ risks of STDs/STIs
Increased risks of getting infected with HIV or the risk of infecting others
High incidences of infertility e.g. pelvic in ammatory disease if untreated result in infertility or tubal pregnancies.
Future problems with pregnancies & child birth
Mental disorders & deaths especially in syphilis Treatment of STDs/STIs
STDs/STIs require medical examination & medical treatment. Any person who has contracted STD/STI & is receiving treatment should also:
Receive counseling from a quali ed health worker on how to avoid future infections
Take all medicines prescribed exactly according to all the instructions
Inform all sexual partners of the need to get examined & treated
Abstain from further risky sexual behaviors
Use condoms for protection
6.3.4. Why teenagers don't seek treatment
Lack of con dentiality
Hostility of service providers
Stigma attached to STIs/STDs
Financial constraints for the youth who are unemployed e.g. anti-fungal drugs( di unisal pessaries) - clears most infection and it costs Ksh.1500 per tablet
Ignorance of availability of service providers
NB: these concerns could be addressed through training service providers to be youth friendly & availing information, education & communication materials to the youth
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6.3.5. FGM (Female Genital Mutilation) It's a destructive invasive procedure usually performed on girls before puberty. It involves surgically removal of part or the whole clitoris using razor blades, knives, and scissors.
Since the victims are young they are unable to give
their informed consent.
FGM is forced on approximately 6000girls per day
world wide. Because of poverty & lack of medical facilities the procedure is frequently done under less hygienic conditions & often without anaesthesia. A person who is not medically trained usually circumcises about 20 girls of same age group.
• Types of FGM 1.
Sunna
- its most widely practiced in sub-Saharan and middle east. It
involves removal of the tip of the clitoris. 2.
Intermediate-it's
where the whole clitoris and adjacent parts such as
labia major and labia minor are removed. 3.
Pharoic - it's the total removal of the clitoris, labia minor, labia major and where the two sides of the vulva are drawn together and then fastened leaving a small opening for urinating and menstruating. This is especially in Somalia.
• Eects of FGM leads to conditions that favours HIV survival They include;
An abnormal anatomy with anatomical distortion
Partial closure of the vagina
Incomplete healing brought about by infections i.e. acids & organisms from urine
Scar formation which may be excessive
Urinary tract infection f ) In ammation of the genital area
Chronic urinary retention - urine is broken down to urea & uric acid accumulates in joints & causes gout.
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Exercise 7.
Revision Questions
Discuss various methods used in HIV/AIDS diagnosis
Example
.
What is CDC's guidance on ART and preventing the sexual
transmission of HIV?
Solution : Know your HIV status-get tested: Knowing whether or not you have HIV is the rst step toward keeping yourself healthy and avoiding passing infection on to others. Continue to get tested regularly if you engage in ongoing risk behavior. If you are HIV infected, know about ART: See a healthcare provider and nd out if you should be on ART. Even if you do not need ART at rst, keep your appointments for check-ups so that you will be able to start when you do need it.
Current guidelines suggest that ART be started when the CD4
cell count is between 350-500. However, it may be started when CD4 counts are greater than 500, depending upon your situation. For example, pregnant women and people with certain medical conditions should start earlier, at higher CD4 counts.
ART can also be started earlier to help prevent HIV
transmission to partners at risk for infection.
Ask your healthcare provider
about when the time is right for you. If you are on ART, take it correctly and consistently: ART drugs work best when the right doses are taken at the right times. Not taking them properly gives the virus a chance to multiply and sometimes become resistant to the medications. Taking ART as recommended will give you the best chance of staying healthy, and will probably help lessen the chance of infecting others. Whether you are infected or not, know what to do to prevent transmission of HIV: Eective ART and an undetectable viral load will probably decrease the risk of transmission, but ART alone will not prevent all new infections. For additional protection, other prevention methods-abstinence, sex only within a mutually monogamous relationship, and condoms-should be used.
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Revision questions or guidelines 1. What are the advantages of pre-test counseling? 2. Explain the expected reactions that might be encountered by an HIV positive individual. 3. State the advantages of knowing ones HIV status. 4. What are the components of home-based care of HIV/AIDS patients? 5. VCT is a powerful weapon in the ght against HIV/AIDS. Explain the role of VCT centers as a HIV/AIDS management strategy. 6. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 7 Prevention and treatment of Hiv/Aids Learning outcomes Upon completing this topic, you should be able to understand:
Prevention and control of mother to child transmission
HIV Post exposure prevention
Classes of drugs used against HIV
Limitations of antiretroviral therapies
Development of new HIV drugs and vaccine
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7.1. Prevention and control of mother to child transmission There are certain factors that may reduce the risk of transmission from mother to baby. They includes:
Taking anti-HIV therapy during pregnancy and delivery e.g. AZT which reduces the viral load.
An elected caesarean section instead of normal delivery
Not breast feeding where there is access to safe, adequate milk substitutes.
Breast feeding should be avoided because the HIV virus is
present in breast milk. Also it is not uncommon for mothers to experience cracked or bleeding nipples while breastfeeding, therefore increase the risk of viral transmission.
Mothers who are HIV positive should not donate breast milk to breast milk barks, neither should they express milk to be bottle fed to their baby.
7.2. Prevention and control of transmission through blood and other blood products
Screening all donated blood especially for transfusion.
Careful handling of blood and body uids
Avoidance of sharp injuries, needles, knives, clips, sharp objects in hospital working situation
Used needles should be disposed in the right tray.
Never pick up a sharp object without looking
Use of gloves (heavy gloves) when you sense danger
Avoid skin/mucous membrane contaminations.
Equipments should be
thoroughly and properly sterilized. This is because HIV is very sensitive and easily destroyed by boiling at least 5 minutes and is susceptible to a wide range of disinfectants
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7.3. HIV Post exposure prevention Studies show that under certain circumstances, administering antiretroviral drugs within 24 hours (preferably within one to two hours) after exposure to HIV can protect a person from becoming infected with the virus. Although the eectiveness of post exposure antiretroviral therapy following sexual exposure to HIV remains uncertain, the Center for Disease Control, USA, recommends that health-care personnel exposed to HIV infection from a needle stick or other accident take antiretroviral drugs.
7.3.1. Ways in which HIV cannot be transmitted
Kissing (except in cases of deep kissing where copious amount of saliva is exchanged), touching, hugging or shaking hands
Sharing crockery and cutlery
Coughing or sneezing
Contact with toilet seats
Insect or animal bites e.g. mosquitoes, bedbugs.
Swimming pools
Eating food prepared by someone with HIV.
7.4. Treatment of HIV
The four main classes of drugs used against HIV are:
Nucleoside Analogue Reverse Transcriptase Inhibitors
Non-nucleoside Analogue Reverse Transcriptase Inhibitors
Protease Inhibitors
Entry Inhibitors
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7.4.1. Nucleoside analogues reverse transcriptase inhibitors These impede the action of reverse transcriptase, the HIV enzyme that converts the virus's genetic material into DNA. During this conversion process, these drugs incorporate themselves into the structure of the viral DNA, rendering the DNA useless and preventing it from instructing the infected cell to make additional HIV. Examples include AZT, didanosine (sold under the trade name Videx), zalcitabine (HIVID), stavudine (Zerit), lamivudine (Epivir), and abacavir (Ziagen)
7.4.2. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) They use a dierent mechanism to block reverse transcriptase. These drugs bind directly to reverse transcriptase, preventing the enzyme from converting RNA to DNA. Three NNRTIs are available: nevirapine (Viramune), delavirdine (Rescriptor), and efavirenz (Sustiva).
7.4.3. Protease inhibitors These cripple protease, the enzyme vital to the formation of new HIV. When these drugs block protease, defective HIV forms that is unable to infect new cells. These drugs are taken orally and act against HIV directly. As the chemicals produced by the new DNA attempts to make copies of HIV, the protease inhibitors act against them and prevent them from working correctly.
New
particles of HIV produced in the presence of protease inhibitors are immature and non-infections.
Examples are saquinavir (Invirase), ritonavir (Norvir),
indinavir (Crixivan), nel navir (Viracept), and amprenavir (Agenerase).
7.4.4. Entry inhibitors They are known as entry inhibitors because the rst stage of the process, whereby HIV enters a CD4 cell is the binding or fusion of the HI virus with a particular part of outer wall of the CD4. The entry inhibitor is a drug speci cally designed to t between the HIV particle and the point of the CD4 cell to which it needs to bind to gain entry and therefore prevent this happening.This is the newest class of anti-HIV drug. The best known drug in this class is T-20, which is taken by injection into a muscular part of the body.
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7.4.5. Limitations of antiretroviral therapies
ARVs have a number of limitations. They include drug resistance, side eect and costs of treatment:
• Drug resistance
Clinical studies of treatment with antiretroviral drugs have showed that their bene ts are short-lived when a single drug is used alone.
This
short-term eectiveness results when HIV mutates, or changes its genetic structure, becoming resistant to the drug. The genetic material in HIV provides instructions for the manufacture of critical enzymes needed to replicate the virus. Scientists design current antiretroviral drugs to impede the activity of these enzymes. The structure of the virus's enzymes changes if the virus mutates. Drugs no longer work against the enzymes, making the drugs ineective against viral infection, and resistance sets.
Genes mutate during the course of viral replication, so the best way to prevent mutation is to halt replication.
Studies have shown that the
most eective treatment to halt HIV replication employs a combination of three drugs taken together, for instance, a combination of two Nucleoside Analogues with a Protease Inhibitor. This regimen is called triple therapy (also known as Highly Active Antiretroviral Therapy - HAART) and it maximizes drug potency while reducing the chance for drug resistance. The combination of three drugs is often referred to as an AIDS cocktail.
In HIV-infected patients who have undergone triple therapy,
the viral loads reduced signi cantly, sometimes to undetectable levels.
Despite phenomenal success, triple therapy has some drawbacks. This multidrug therapy is quite complicated, requiring patients to take anywhere from 5 to 20 pills a day on a speci c schedule. Some drugs must be taken with food, while others cannot be taken at the same time as certain other pills.
Even the most organized people nd it di cult to
take pills correctly. Yet, just one or two lapses in treatment may cause the virus to develop resistance to the drug regimen
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• Drug side eects
Many people also nd it di cult to deal with the unpleasant side eects produced by antiretroviral drugs. Common side eects include nausea, diarrhea, headache, fatigue, abdominal pain, kidney stones, anemia, and tingling or numbness in the hands and feet. Some patients may develop diabetes mellitus, while other patients develop collections of fat deposits in the abdomen or back, causing a noticeable change in body con guration. Some antiretroviral drugs produce an increase in blood fat levels, placing a patient at risk for heart attack or stroke. Some patients suer more misery from the drug treatment than they do from the illnesses produced by HIV infection.
To decrease the toxic eects of drugs and to defer costly therapy, it advisable to delay drug treatment for HIV infection in people showing no symptoms and who have been infected with HIV for more than six months. The new guidelines call for delaying treatment until an infected person's CD4 cells fall below 350 cells per microliter of blood or the HIV viral load exceeds 30,000 per microliter of blood. Evidence suggests that delaying treatment poses no harm to infected people and, in fact, bene ts them by deferring the toxic side eects of the drugs.
• Cost of treatment
The greatest drawback to triple therapy is its high cost, which is well beyond the means of people with low incomes or those with limited health-care facilities. As a result, the most eective therapies currently available remain beyond the reach of the majority of HIV-infected people worldwide.
7.4.6. Development of new HIV drugs and vaccine
Scientists continue to develop more powerful HIV treatments that have fewer side eects and fewer resistance problems. Some drugs under investigation block the HIV enzyme integrase from inserting viral DNA into the infected cell.
Other drugs prevent HIV from binding with a
CD4 cell in the rst place, thereby barring HIV entry into cells.
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Some scientists focus on ways to fortify the immune system. A biological molecule called interleukin-2 shows promise in boosting the immune system's arsenal of infection- ghting cells. Interleukin-2 stimulates the production of CD4 cells. If enough CD4 cells can be created, they may trigger other immune cell responses that can overpower HIV infection.
In other research, doctors hope to bolster the immune system with a vaccine. Most vaccines available today, including those that prevent measles or poliomyelitis, work by helping the body to create antibodies.
Such
vaccines mark speci c infectious agents, such as the measles and polio viruses, for destruction. But many experts believe that an eective HIV vaccine will need to do more than just stimulate anti-HIV antibodies. Studies are underway to develop vaccines that also elevate the production of T cells in the immune system.
Scientists hope that this dual
approach will prime the immune system to attack HIV as soon as it appears in the body, perhaps containing the virus before it spreads through the body in a way that natural immune defenses cannot.
7.4.7. Challenges in Developing AIDS Vaccines
HIV continually mutates and recombines. This may mean that a vaccine would need to protect the person against many strains of the virus. Vaccines against other viruses have only had to protect the person against one or a limited number of strains.
HIV infects helper T cells, the immune cells that orchestrate the immune response. It is very di cult to design a vaccine that, to be eective, needs to activate the very cells the virus infects. HIV can be transmitted as both free virus and in infected cells.
This may mean that both arms
of the immune system (humoral and cellular mediated) may need to be stimulated.
Researchers do not know what constitutes an eective immune response to HIV. It might be antibodies, activated immune cells, perhaps a third immune response, or a combination of immune responses. Researchers lack an ideal animal model for AIDS vaccine testing
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7.4.8. Treatment of opportunistic infections
In addition to antiretroviral therapy to combat HIV infection, eective drug treatments are available to ght many of the medical complications that result from HIV infection. Doctors try to prevent infections before they begin to avoid taxing a patient's weakened immune system unnecessarily.
A doctor instructs an HIV-infected person on ways to avoid
exposure to infectious agents that produce opportunistic infections common in people with a weakened immune system. Doctors usually prescribe more than one drug to forestall infections. For example, for those who have a history of pneumocystic pneumonia and a CD4 cell count of less than 200 cells per microliter, doctors may prescribe the antibiotics sulfamethoxazole and trimethoprim to prevent further bouts of pneumonia. Patients suering from recurring thrush may be given the antifungal drug uconazole for prolonged periods. For people with CD4 cell counts of less than 100 cells per microliter, doctors may prescribe clarithromycin or azithromycin to prevent Mycobacterium avium infections.
• Support mechanisms
A person diagnosed with HIV infection faces many challenges, including choosing the best course of treatment, paying for health care, and providing for the needs of children in the family while ill. In addition to these practical considerations, people with HIV infection must cope with the emotional toll associated with the diagnosis of a potentially fatal illness. The social stigma that continues to surround a diagnosis of AIDS because of the disease's prevalence among gay men or drug users causes many people to avoid telling family or friends about their illness. People with AIDS often feel incredibly lonely as they try to cope with a devastating illness on their own. Loneliness, anxiety, fear, anger, and other emotions often require as much attention as the medical illnesses common to HIV infection.
Counseling centers and churches provide individual or group counseling to help people with HIV infection or AIDS share their feelings, problems, and coping mechanisms with others. Family counseling can address the emotions of other family members who are disturbed by the diagnosis
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of HIV infection in another family member. Grief counseling also helps people who have lost friends or family members to AIDS.
Voluntary Counselling and Testing Services (VCT) Counselling is advice or guidance, especially as provided by a professional in a given eld. Counselors are people who are trained to help others to understand their problems, identify and develop solutions, and make their own decisions about what to do.
Counselling involves being with them, listening to
them talk about their problems and fears, helping them to increase their own self-esteem, and when necessary giving correct and useful information based on what they need to know at that point in time. Voluntary counselling and testing (VCT) is an important strategy for management of HIV/AIDS. It is a powerful weapon in the ght against HIV/AIDS since it is associated with behaviour change that reduces HIV transmission and serves as a point of entry into care for those testing.
The national VCT programme uses four models of service delivery:
integrated,
stand-alone,
community-based
and mobile.
In integrated sites, a VCT centre is usually located within the grounds of health facilities such as hospitals, health centres or dispensaries. Standalone sites are usually not associated with any existing medical institution and usually have sta fully devoted to VCT. They are largely operated by non-governmental agencies and are usually located in densely populated urban areas.
In the community-based sites, VCT is either
integrated into other social services or implemented as the sole activity of a local community-based organization (CBO) or a faith-based organization (FBO). In the mobile sites VCT is provided as an outreach to remote or hard-to-reach communities where other models of VCT are either not feasible or unavailable.
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There may be any number of reasons why a person may want to undergo a test to discover whether they are HIV positive.
Medical reasons for testing
*
Pregnancy
*
STDs
*
Legal insurance,
*
visas, s
*
cholarships
Voluntary testing
*
Desire to know HIV status
*
For those expecting to marry/for future partnership.
*
Experiencing symptoms indicative of HIV.
7.4.9. Steps involved in HIV testing in VCT
• Pretest counseling HIV counseling is an eective public health intervention because it promotes the health of HIV infected persons and plays a role in reducing HIV transmission. Aims of a pretest counseling Ensure you have a full understanding of the implications of the test and are able to make an informed decision whether to test. Ensure informed consent (to carry out the test) is gained from you. Give you the opportunity to discuss routes of HIV transmission Discuss the implications and support needs that may follow either appositive or negative test result. Consider ways to reduce transmission or contraction of the virus in the future. Encourage you to consider and evaluate the impact the result may have on you emotionally, physically and in relation to your lifestyle. Helps to identify risk factors and symptoms that may indicate that the patient is HIV infected. During the pretest counseling the person thinks of someone to share the results with. To reduce the internalized stigma by providing information about HIV in a neutral environment.
• Advantages of testing 1. Ability to seek medical intervention when one tests positive and this prevent complications of AIDS.
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2. To prevent transmission to others 3. To make healthy life style changes -eat well, exercise. 4. Important also to know cause for various symptoms.
• Disadvantages 1. Increased fear of illness and death 2. Fears related to family relations/parenting 3. Guilt of past relationships and sexual behaviour 4. Stigma associated with HIV/AIDS The patient should be helped to understand the antibody test. Body produces antibodies to HIV that are found in the blood. Positive test mean the person is HIV infected. There is a period of 3-6 months during which antibodies may not show up in the blood and test will reveal the person to be negative. This is the window period. Tests giving negative results should be repeated again after 3 and 6 months respectively.
• Post test counseling If the person test positive:
Explain to them that there is chance of not developing full blown AIDS by medical intervention -ARVs, antibiotics and antifungal, nutrition and reducing stress, and change of lifestyle through positive living.
If results are negative:
Clarify that the test did not yield positive results does not means that the person does not have HIV or has not developed HIV.
Let the person know that there is need to repeat test after 3 months however don't forget to congratulate the person.
Discusses methods to reduce risk of transmission and avoiding risky behaviours.
Discuss the current risk situations of the patient and help to develop strategies to increase prevention of transmission.
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• Role of VCT centers 1. VCT has taken a central role in enlightening and guidance of HIV/AIDS disease. 2. Contribute immensely in the control of HIV/AIDS 3. Involve testing and availing the results to people in minutes. 4. Before testing the people are prepared rst for both positive and negative results before allowed to know their status. Importance of knowing one's HIV status includes:
(a) Preventing the uninfected person from contracting the disease (b) Enhancing abstinence for the infected helps in controlling the disease through self awareness and putting up ways on how to abstain or get involved in safe sex
5. Counseling also helps in ensuring reduced spread of the virus by those people who have been infected but had not shown symptoms. 6. Counseling infected people, majority of who have lost hope, helps in ensuring positive living. 7. Help to reduce the revenge attitude for those innocently infected and may opt to die with many or commit suicide. 8. Counseling enables the public who includes the relatives of the infected to stop stigmatizating those infected to be able to live normal lives knowing that someone cares for them. 9. Testing also helps the government to keep statistics on the prevalence of the disease hence policy development or strategic planning.
• General reactions to testing HIV positive Each of these feelings or reactions is part of a normal response to a situation of great stress.
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A person might move from one response to the next in a progression leading nally to acceptance of their situation, or more commonly their feelings will keep changing. One day they might feel rejected and lonely - the next day hopeful and energetic. One day depressed, another day angry.
Shock - No matter how much someone prepares, it is a shock to learn that one has HIV infection or AIDS. A person might feel confused and not know what to do.
It is good for people to be with someone they
trust at this time.
Denial - At rst they might not be able to believe that they really have HIV or AIDS They might think 'The doctor must be wrong' or "It can't be true - I feel so strong". Not wanting to believe is a strong force that people may use subconsciously to protect themselves from the threat posed by AIDS.
Anger - People might become very angry when they learn that they have HIV or AIDS This is a common feeling and can come when they blame themselves or the person they think gave them HIV. Some may even blame God. Talking to someone can help a person overcome feeling of anger and help them accept their situation.
Bargaining - A person with AIDS might try to bargain, thinking that God will cure me if I stop having sex or the ancestors will make me better if I slaughter a goat or I will be good and AIDS will go away. People with HIV or AIDS need to be helped to get through the feeling of bargaining.
Fear - People with HIV or AIDS fear many things, for example:
Pain of losing their job
Other people knowing that they are infected
Rejection
Leaving their children
Death.
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Loneliness - A person with AIDS might often feel lonely.
This feeling
may come and go for a long time and depends on the support given by family and friends. Anyone who has AIDS must be helped to remember that they are not alone; that they are surrounded by family, friends and a community that cares about them. Many other people have HIV or AIDS.
Self-consciousness - When a person has HIV or AIDS they might think everyone is looking at them or talking about them.
This may make
them want to hide. Sometimes a person with AIDS may feel unworthy of friendship.
Depression - If a person nds out that they have HIV or AIDS they may feel there is no good reason for living. They may feel useless, and want to stay at home, not eat, and not talk to anyone. Depression can make someone weak both in mind and body.
Acceptance - After some time, a person with HIV or AIDS will usually begin to accept their situation. This will help the person to feel better. Such a person will feel more peaceful in their mind, and will begin to think about the best ways to live.
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Revision Questions Example
.
Prevention involves tackling the most important modes of trans-
mission. Discuss brie y how to prevent sexual transmission.
Solution :
Taking anti-HIV therapy during pregnancy and delivery e.g. AZT
which reduces the viral load. HIV positive mothers to choose an elected caesarean section instead of normal delivery. Not breast feeding where there is access to safe, adequate milk substitutes.
Breast feeding should be avoided
because the HIV virus is present in breast milk. Also it is not uncommon for mothers to experience cracked or bleeding nipples while breastfeeding, therefore increase the risk of viral transmission.
Mothers w ho are HIV positive
should not donate breast milk to breast milk barks, neither should they express milk to be bottle fed to their baby.
Exercise 8.
Discuss the role of Voluntary Counseling and Testing (VCT)
centers in HIV/AIDs management
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Revision questions or guidelines 1. Discuss HIV/AIDS prevention and control strategies 2. Explain the factors that account for the continued rise in women infected with HIV compared to men. 3. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 8 Concept of positive living Learning outcomes Upon completing this topic, you should be able to understand the following:
Components of home based care
Relationship between good nutrition and management of HIV
Reducing the risk of transmission during pregnancy
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8.1. Introduction The rst stage of positive living is accepting wholly HIV is part of you and this cannot be changed and start taking good care of yourself: 1. Breath - When you get overwhelmed, take three deep breaths. Breathing better is one of the most important things you can do to maintain your health. It improves everything from chronic health problems, stress related disorders to our sporting performance. Whether you want to boost your workout, ease stress or improve your health, learning to breathe properly can enhance your quality of life.
Look for fresh air, like the
around lakes, forests, near rivers and water falls, at the seashore and after a rainstorm that is know to contain abundant negatively charged ions.. This kind of air is refreshing and gives people a lift. House plants also do more than enhance the appearance of the home and o ces. They enrich the air with oxygen and absorb carbon dioxide. Some even remove toxic pollutant from the air we breathe (Ang'awa 2005).
Bad air and
poor breathing habits interfere with breathing, reducing the oxygen delivered to the blood and impairing performance and mood and promotes negative emotions like depression, irritability, headaches and feelings of fatigue and exhaustion because the body is robbed of this vital element (Ang'awa 2005) 2. Refuse to be a victim - Focus on what you can do. Focus on living with HIV and not dying of AIDS. Live one day at a time. Seek support not pity 3. Educate yourself about HIV - Attend HIV/AIDS seminars, workshops or any education forum. 4. Physical exercise - Necessary for all parts of the body 5. Reduces stress
(a) Keep busy (b) Do not concentrate on self. (c) No self pity, concentrate on development
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(d) Do not overwork.
6. Express yourself, ask for support -
(a) Talk to your friends (b) Share feelings with your partner, friends and family (c) Professional counselor, therapists and clergy can oer support
7. Embrace your own spirituality
(a) Faith based organizations have ministers who support HIV positive people (b) If you feel angry with God, acknowledge it. HIV is a virus not a punishment.
8. Think and act positively 9. Seek out people who are honest, trustworthy and supportive 10. Cry when you need to let it out, as it creates room for positive feelings 11. Accept responsibility - Pledge that HIV stops with you. liberately seek to infect others.
Do not de-
Use condoms to pr others and avoid
re-infection. 12. Talk to other people with HIV - group therapy works.
Join support
groups 13. Healthy and diet - eat well balanced diet with lots of proteins and vitamins Avoid food poisoning as much as possible Avoid alcohol, drug and substance abuse 14. Attend to opportunistic infections immediately 15. Have hope about many things. For example:
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It is important to have hope.
Hope lifts spirits and gives strength to face
each situation. Hope can help each person to ght HIV and AIDS - to live positively and to live longer. Remember, even if a person has hope today, it is possible to feel angry or depressed tomorrow. This is normal. Even people without HIV or AIDS go up and down emotionally every day. The important thing is to try to instill the feelings of hope again and again.
8.2. Home Based Care Home based care means - any form of concern given to sick people in their own dwellings. It can mean the things people might do to take care of themselves or the care given to them by the family or it can be extended from the hospital or health facility to the patient's home through family participation and community support (Gilks et al. 1998., MOH 2002c). Care includes physical, psychosocial and spiritual activities. The term family here refers to the person (or people) with the main responsibility for caring for a person with AIDS in the home.
In fact, the person providing such care may be a blood relative,
a relative by marriage (a spouse for example), a friend, a neighbour or some other person. The overall goal of home based care is - to ensure a high standard of human, holistic care that meets the needs of People living with HIV/AIDS (PLWA's). PLWA's have basic, physical, economic and psychosocial needs. These can be met at the familiar home environment and may lead to an improvement of the quality of life for PLWA's. Home based care establishes an important link between health professionals and the caregivers at home. HIV /AIDS aect all aspects of social and economic life in Kenya.
The
health sector is aected by an increased burden of caring for those infected. It is responsible for delivering eective treatment of opportunistic infections, providing compassionate care and implementing many prevention programs such as STD control, condom promotion and distribution and health education and provision of Anti retroviral drugs (ARVs). It is estimated that 51 % of the bed occupancy in public hospitals in Kenya is by AIDS patients1.
The national health systems cannot cope with the
accelerating demand as increasing number of people with full blown AIDS develop opportunistic infections. The nancial investments required to treat
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AIDS are beyond national budgets. Not only is the cost of care beyond health care systems, but it is beyond the reach for the individual and the family. Family, friends and the community must ll the "care gap" at large. This group of care givers has the capacity and resources to do more than the national health care systems: they take care of the sick, replace their labor/income, care for their dependants, and help defray costs associated with the illness, provide palliative care of PLWA's and quality life in death.
The use of caregiver is
instrumental in reducing the stigma associated with HIV/AIDS. Thus, the concept of home based care.
8.2.1. Rationale for Home Based care
The people living with HIV/AIDS are discharged from hospital where trained professionals are and sent home where they are usually cared for by untrained relatives
PLWA's need continued quality care to prolong lives and reduce suering
There are limitations on hospital care, including limited resources that aect the care that can be given to PLWA's. Continued hospitalization of PLWA's may lead to depletion of family and community savings and investments.
8.2.2. Advantages of organized home based care
It aects the socioeconomic, psychosocial and medical well being of the patient, the family, the community and the health care system.
It provides comfort of a familiar environment to the PLWA,
It is less expensive for families
It helps counteract the myths and mistaken beliefs about HIV/AIDS
It encourages people to take steps to prevent infection.
It encourages community participation in the care of PLWA's and thus maintains community cohesiveness in responding to community members' needs.
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It eases the demand on the national health system by reducing crowding in hospitals, thus better care is given to those who really need to be in hospital.
8.2.3. Components of home based care
Clinical management - which includes early diagnosis, rational treatment and planning for follow up care of HIV related illness
Nursing care - which includes care to promote and maintain good health, hygiene and nutrition
Counseling and psycho social care - which includes reducing stress and anxiety, promoting positive living, and helping individuals to make informed decisions on HIV testing, plan for the future and behavior change
Social support - which includes information and referral to support groups, welfare services and legal advice for individuals and families and where possible provision of material assistance
8.2.4. Aspects of nutrition in comprehensive care of HIV/AIDS patients Nutrition implies the process of absorbing nutrients from food and processing them in the body in order to keep healthy or to grow. Adequate food security in the household is requisite for optimum nutrition, health and survival (FAO 2002). But HIV/AIDS reduces the household's ability to produce and buy food by taking away the adult labour that would otherwise be engaged in agricultural production or in earning an income. increases health expenditure.
At the same time, HIV disease
The capacity of an aected household to ob-
tain an adequate amount and variety of food, and to adopt appropriate health and nutritional responses to HIV/AIDS, especially for the already vulnerable ones, is grossly reduced. On the other hand both HIV/AIDS and malnutrition compromise the immune system, resulting in increased susceptibility to severe illnesses, which reduce the quality of life and shorten life expectancy.
Mal-
nutrition due to HIV/AIDS is linked to inadequate food intake, poor uptake of food into the body, and poor use and storage of nutrients. Each of these factors must be considered in providing the most appropriate nutritional care
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for the HIV-positive person. Reduced food intake in persons with HIV may be due to painful sores in the mouth and throat, loss of appetite, or fatigue. The main causes of loss of appetite are infections and depression. Other causes include side eects of medication such as nausea and vomiting, and inadequate access to and availability of appealing foods. Poor absorption of nutrients results when HIV damages the small intestine and alters the healthy bacteria of the digestive system, causing malabsorption of fats and carbohydrates and frequent episodes of diarrhea. Intestinal infections also cause diarrhea, with loss and waste of nutrients. Infections, including HIV itself, lead to increased requirements for energy and protein, ine cient use of nutrients, and loss of nutrients. Energy requirements are likely to increase by 10% to maintain body weight and physical activity in adults and growth in symptomatic children.
• Advantages of good nutrition to PLWA
Good nutrition entails eating a well-balanced diet that contains all the nutrients the body needs for growth and proper functioning. Balanced nutrition helps the body to:
Increase resistance to infection and disease and improve the energy supply.
Boost the immune system and therefore reduce the frequency of episode of morbidity.
Lessen severity of infection, improve the response to treatment for opportunistic infections such as TB, and speed the rate of recovery.
Replace lost micronutrient and provide the body with all essential nutrient required for good health.
Preserve muscle mass, slow or stop the loss of lean tissue, prevent weight loss, and improve body strength and energy.
Delay the rate of progression of HIV to AIDS and the further advance of AIDS itself.
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Keep PLWAs alive and able them to lead an active life; this in turn reduces their dependence, thus allowing them to take care of themselves and to delay early orphan hood of their children.
Studies show that nutrition interventions can positively aect nutrition status (FAO 2002), the immune system and even personal esteem, by maintaining body weight, improving eectiveness of medication and prolonging life. Supplementing micronutrients has been shown to increase life expectancy of subjects with fewer than 200 CD4 cells per millilitre1. A number of micronutrient supplements including vitamin A, zinc and iron have been found to boost the immune system in a person with HIV infection. Multivitamins can reduce the risk of death and improve immune function.
• Principles of nutrition support for PLWA Good nutrition can therefore play an important role in the comprehensive management of HIV/AIDS, as it improves the immune system, boosts energy, and helps recovery from opportunistic infections.
The following basic principles
are being advocated for all programmes of HIV/ AIDS patient management, counselling or education:
Nutritional education and counselling
Water and food safety intervention to prevent diarrhoea
Income-generating activities to enhance food security
Nutritional supplementation
Meal designing and planning using locally available foodstus
To avoid malnutrition and wasting away HIV infected persons should always ensure that they take highly nutritive foods that are well balanced.
High protein diet to build up infected cells and tissues/strengthen them. They include Soya beans, lean meat, milk, beef, eggs.
Carbohydrate foods are required in large quantities to provide the much required energy to strengthen patients who are weak.
They include
Whole meal cereals, cassava, potatoes, and cooked bananas.
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Vitamins and minerals help bodies' in ghting diseases and keep opportunistic infections checked. They also help in a quick recovery and disease management. Vitamins are obtained from fresh vegetables, fruits, fresh juices.
Fluids help in cleaning the immune system, blood puri cation and to improve the appetite (anorexia).
Frequency of food intake should be high to avoid or replace weight loss
8.3. Management of pregnancy in HIV/AIDS The introduction of combination therapy and the impact it has had on improving the health of HIV-positive women, together with the enormous strides made in reducing the risk of transmission from mother to baby has led more HIV positive women contemplating having children. It is advisable to plan a pregnancy well in advance, more so for HIV positive women. Unfortunately, prior planning is not possible for all HIV positive women some will learn of their HIV diagnosis at routine antenatal visit. The women will be promptly referred for additional costs and informed of treatment options to safeguard their own health and the health of their unborn child. Ideally HIV positive women should be seen by specialist midwife and/or obstetrician throughout their pregnancy. This will ensure that both the pregnancy and their HIV can be closely monitored and any additional information, treatment and support made available. HIV positive women should discuss the prospect of pregnancy before hand, ensuring they have the information to ensure the best possible chance of a safe, healthy pregnancy and delivery.
8.3.1. Reducing the risk of transmission during pregnancy This is achieved by antiretroviral therapy. From conception onwards there is a risk of viral transmission from mother to baby. This is increased if;
The mother has high viral load
She is old
She smokes during pregnancy
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She has unprotected sex during pregnancy.
She uses illicit drugs during pregnancy
She has no antiretroviral therapy during pregnancy and delivery
Membrane rapture more than 4 hours before delivery
Delivery is natural and not by caesarean section.
Delivery is prolonged or di cult
Cervical or vaginal infection is present
Membranes are in amed
The mother breastfeeds
Primarily, viral load is the most important factor to in uence the risk of transmission. A high viral load substantially increases the risk of transmission to either a negative partner or unborn child. For this reason, the control of viral load from conception, throughout the pregnancy and during delivery by use of antiretroviral therapy is crucial at speci c pregnancy stages.
• Conception Conceiving a child in relationship where one partner is HIV positive and the other HIV negative presents unique challenges.
If the woman is the HIV
positive partner, arti cial insemination oers the best chance of conception while not risking transmission to her partner. For some couples, assisted conception is not an option and they may choose not to use a condom while trying to conceive a child naturally, this of course increases the risk of HIV transmission to the negative partner.
In these in-
stances it may be wise to restrict unprotected sex to the fertile period of the woman's cycle.
• The pregnancy Optimum health, which for an HIV-positive woman means a low viral load and a healthy CD4 count in addition to good general health, oers the best chance for a healthy pregnancy and baby. There is no evidence to suggest that
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pregnancy accelerates HIV progression. It has been observed that CD4 counts drop in pregnancy, but this is also seen in HIV-negative women. CD4 count usually returns to a pre-pregnancy level soon after delivery. ARVs such as AZT are used to reduce the risk of transmission during pregnancy. AZT is taken orally after the 14th week of pregnancy and intravenously during labour. Administering AZT syrup to newborns for the rst six weeks can further reduce transmission. AZT reduces the risk of mother to child transmission by lowering the mother's viral load during pregnancy and delivery and may act as a post exposure treatment for newborns.
It is the
only antiretroviral that has been thoroughly tested for use in pregnancy. For women who are already taking antiretroviral therapy and other discover they are pregnant after 14 weeks, it is usually advisable that they continue with the establishment therapy as well as AZT.
• Delivery There are con icting opinions regarding whether HIV positive mothers should undergo a vaginal delivery or a planned caesarean section to reduce the risk of transmission to their baby. Until recently all HIV positive mothers were urged to have an elective caesarean. The decision relating to mode of delivery is one that should be reached after all factors have been considered by the mother and her doctor.
• Breastfeeding HIV- positive mothers should not breastfeed their babies as this increases the risk of transmission especially if the mother has a cracked or bleeding nipples and if the baby if teething.
• Testing babies for HIV All babies born to HIV positive mothers will be tested to ascertain whether the virus has been transmitted. Initial testing is undertaken when the child is 48 hours old. Negative children are tested again at day 14 when PCR will identify approximately 90% of infected children. If at 14 days they still test negative, then the test is repeated again at 4-8 weeks and then again at 16-26 weeks of age. If they return two negative results, when they are over 6 month of age, it can be con rmed that the virus has not been transmitted.
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Exercise 9.
Revision Questions
Describe how early detection and treatment of sexually transmitted infections (STIs) are important? Exercise 10.
Explain if one might have been exposed to HIV is there
anything I can do?
Example Solution :
.
Why is HIV testing and counselling important?
More than 90% of people infected with HIV do not know their
HIV status. Voluntary testing and counseling have proved to be an eective public health strategy as they result in reduced risk behaviours and increased condom use. Testing and counselling serve as entry points to HIV/AIDS care and support.
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Revision questions or guidelines 1. Discuss ways employed by the Kenyan government to reduce the impact of HIV/AIDs. 2. Socio-economic and cultural factors greatly contribute to the rapid spread of HIV/AIDS. Discuss. 3. Empowering women in Kenya will contribute towards lowering new cases of infection with HIV. Discuss this statement siting examples. 4. Discuss the role of religion in ght against HIV. 5. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 9 Behavioral patterns and the spread of Hiv /Aids Learning outcomes Upon completing this topic, you should be able to know policies and rights of PLWHAs with relation to:
Individual Behavioral Patterns and the spread of HIV /AIDS
Role of gender in transmission of HIV /AIDS
Drug/Alcohol use and use and the spread of HIV/AIDS
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9.1. Individual Behavioral Patterns and the spread of HIV /AIDS Behaviour can be de ned as all those process by which an organism senses the external world and the internal state of its body and responds to changes which perceives. Many of such process will take place inside the nervous system and may not be directly observable. An organism may respond by involving in a violent activity or incomplete inactivity, but all are equally behaviour. The spread of HIV primarily depends on individual's sexual behaviour patterns how often men and women have sex and who they have sex with. Not everyone's sex life is the same and patterns of sexual behaviour are strongly in uenced by social, cultural and psychological factors over which men and women have little control.
In most societies, men are generally expected to be strong leaders,
to be primary providers of their family's food, shelter and defend themselves, their families and societies from aggressors. Virility-the ability to perform sex is almost an essential component of masculinity in almost every society. Young people are expected to prove their sexual prowess and there is under spread belief that a man's need for sex is beyond control.
For men anything that
appears to interfere with their sex lives such as appeal to abstinence or use of condoms is a threat to their masculinity. Impelled by these attitudes, men on average report more sexual partners than women. The implication of this are that women are likely to contract HIV but less likely to transmit the virus to other sexual partners while men are more likely to contract and transmit the virus. In the long term this means that more women than men will contract HIV. Compounding this situation is the fact that many men do not consider sex as a consensual activity. Sex has to take place when man decides and without a condom if he chooses. Wives are often beaten or ejected from their home. If they refuse to submit to their husbands and many women are at risk outside the home if they refuse to submit to their husbands and many women are at risk outside the home. In such instances, women nd it impossible to protect themselves from infection with HIV or other STI's. In prisons or other single sex environments some men rape other men either as a substitute for sex with a woman or to establish power over their victims. In other situations, however, sex between men may be an expression of mutual desire or the result of ones desire and other's nancial need. There is need to change men attitudes and subsequent behaviours. Men do not protect themselves because male attitudes
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tell them not to; while women do not protect themselves because men do not allow them to.
9.1.1. Behaviour change could play a greater role in reducing HIV infection If individuals could: 1. Postpone their rst sexual intercourse. 2. Practice safe sexual practices 3. Reduce the number the number of sexual partners 4. Prevent and treat STDs 5. Avoid traumatic sexual intercourse 6. Make sex a consensual activity, openly discuss sex issues etc.
9.1.2. Safe sex and safer behaviors
Practice abstinence.
Reduce the number of sexual partners to one.
Always use latex condoms with a water-soluble lubricant containing the spermicide nonoxynol 9 and do not reuse condoms.
Do not use cervical caps or diaphragms without using a condom as well.
Always use dental dams for oral female genital or anal stimulation.
Avoid anal intercourse because this practice may injure tissues.
Avoid manual - anal intercourse ( sting).
Do not ingest urine or semen.
Avoid having sex with people who are injecting drug users.
Engage in nonpenetrative sex such as body massage, social kissing (dry), mutual masturbation, fantasy, and sex lms.
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If female, avoid pregnancy if you or your sexual partner is HIV seropositive.
Inform prospective sexual partners of your HIV-positive status.
Notify previous and present sexual partners if you learn that you are HIV seropositive.
If HIV seropositive, do not have unprotected sex with another HIVseropositive person because cross-infection with another HIV strain can increase the severity of the disease.
Do not share needles, razors, toothbrushes, sex toys, or other bloodcontaminated articles.
If HIV seropositive, do not donate blood, plasma, body organs, or sperm
9.2. Role of Gender in HIV/AIDS Transmission Although women are making eorts towards equality with men, a lot of them still do not have control over their lives especially their bodies.
9.2.1. Cultural, social, biological and economic pressures make women more vulnerable HIV that men. 1. Men still dictate matters regarding sex - for example, when to have sexual intercourse irrespective of whether a woman wants it or not. Also use of condom relies on the man. 2. Girls have been taught to leave decision making on sex matters to males whose needs and demands are expected to dominate. 3. Male predominance often comes with intolerance for predatory and violent sexuality - this carries double standards whereby women are blamed or thrown out for in delity whether real or suspected while men are allowed to have multiple sexual partners. 4. Biological makeup and reproductive anatomy of the female body makes her to be more vulnerable to contract HIV than men - sex takes place inside the body of the woman and the female genitalia is prone to tears
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and wear. These tears and wears and/or sores provide entry route for the virus. 5. The female reproductive system is also in direct and longer contact with the male semen deposited during sexual intercourse. If the semen has HIV, then it becomes easier for her to contract the virus. 6. Poverty - failure to respect the human rights of girls in terms of equal access to school, training, employment opportunities etc. reinforces their economic dependence on men. A woman who is in a stable relationship and is economically dependent on her husband cannot aord to jeopardize his support even when she suspects that he is HIV positive. If she insists on a condom use she is accused of being unfaithful or the man reacts violently. 7. Prostitution-a lot of women go into prostitution as a way of income generating activity. A lot of them end up acquiring HIV/AIDS. For some women, prostitution is a choice while others are forced by circumstances into it to exchange sex for basic necessities of life for themselves and their children. 8. Cultural practices-a number of cultural practices have increased the vulnerability of women to contracting HIV. These include wife inheritance, polygamy, early marriages and resistance to condom use. 9. Social evils - they include rape, sodomy, homosexuality, premarital, extramarital sex, and drug and alcohol abuse. 10. Ignorance - majority of women are poorly educated and lack information on their bodies, HIV/AIDS and other sexually transmitted diseases. They are therefore unable to protect themselves.
A vulnerable woman is one who is lacking in power or control over her risk of HIV infection.
9.2.2. Remedy to above problem 1. Combating ignorance:
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(a) improve the access of girls to formal education, (b) ensure they have information on their bodies, HIV/AIDS and other STD's, and (c) equip them with skills to say NO to unsafe sex.
2. Provide women friendly services
(a) girls and women should have access to appropriate health care and HIV/STD prevention services, (b) make condoms and STD care are available where women don't feel embarrassed.
3. Make female condoms available - female condoms though expensive should be made available. 4. Build safer norms - support organizations advocating against behavioral traditions which have become deadly with the advent of HIV/AIDS e.g. genital mutilation, child abuse, rape, sexual coercion. 5. Educate boys and men to respect girls and women - this enables them to engage in responsible sexual behavior and to share their responsibility for protecting themselves, their partners and their children from HIV/AIDS and STDs. 6. Reinforce women's economic independence - increase and strengthen existing training opportunities for women, credit programmes, saving schemes and women's cooperatives and link them with AIDS prevention activities. 7. Reduce vulnerability through policy changes - policies from communities to national level must be reshaped if women's vulnerability to HIV is to be reduced. Human rights and legal rights should be improved.
9.3. Drug/Alcohol Use and Abuse and the Spread of HIV/AIDS A drug can be de ned as any substance that aects the function of living cells, used in medicine to diagnose, cure, prevent the occurrence of diseases
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and disorders, and/or prolong the life of patients with incurable conditions Drug abuse is characterized by taking more than the recommended dose of prescription drugs such as barbiturates (depressants) without medical supervision, or using government-controlled substances such as marijuana, cocaine, heroin, or other illegal substances. Legal substances, such as alcohol and nicotine, are also abused by many people. Abuse of drugs and other substances can lead to physical and psychological dependence. Drug abuse can cause a wide variety of adverse physical reactions. Long-term drug use may damage the heart, liver, and brain. Drug abusers may suer from malnutrition if they habitually forget to eat, cannot aord to buy food, or eat foods lacking the proper vitamins and minerals.
Individuals who abuse injectable drugs risk
contracting infections such as hepatitis and HIV from dirty needles or needles shared with other infected abusers. One of the most dangerous eects of illegal drug use is the potential for overdosing that is, taking too large or too strong a dose for the body's systems to handle. A drug overdose may cause an individual to lose consciousness and to breathe inadequately. Without treatment, an individual may die from a drug overdose. Drug addiction is marked by a compulsive craving for a substance. Successful treatment methods vary and include psychological counseling, or psychotherapy, and detoxi cation programs medically supervised programs that gradually wean an individual from a drug over a period of days or weeks.
Detoxi cation and psychotherapy are often
used together. The illegal use of drugs was once considered a problem unique to residents of poor, urban neighborhoods. Today, however, people from all economic levels, in both cities and suburbs, abuse drugs. drugs to relieve stress and to forget about their problems. may predispose other individuals to drug addiction.
Some people use Genetic factors
Environmental factors
such as peer pressure, especially in young people, and the availability of drugs, also in uence people to abuse drugs.
People with alcohol use disorders are
more likely to contract HIV than the general population.
Similarly people
with HIV are more likely to abuse alcohol in their life time. In persons already infected, the combination of heavy drinking and HIV has been associated with increased medical and psychiatric complications, delay in seeking treatment, poor HIV treatment outcome.
People who abuse alcohol are more likely to
engage in behaviors that place them at risk of contracting HIV. Heavy alcohol
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use has been correlated with a high risk sexual behaviors including:
Multiple sex partners
Unprotected intercourse
Sex with high risk partners
9.3.1. Relationship between drug use and HIV
Shared needles/syringes for use in drug application can carry HIV and hepatitis viruses.
Drug use is linked with unsafe sexual activity.
Infected blood drawn into the needle is infected along with the drug by the next user.
A recent study has shown that HIV can survive in a used syringe for at least 4 weeks.
A lot of people believe that sex and drugs should go together. Drug users might trade sex for drugs.
Others think that sexual activity is more enjoyable when they are using drugs.
Drug use including alcohol increases the chance of not using protection during sex, leads to acquiring/transmitting HIV/AIDS.
A lot of drugs interfere with the proper functioning of the antiretroviral drugs.
One who is a drug addict might forget to take his ARV therapy - delay in treatment and increment of viral load.
A probability of overdose which is fatal
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Exercise 11.
Revision Questions
Discuss gender vulnerability of HIV infection in females relative to male counterparts
Example
.
Discuss the eects of stigma and discrimination on the spread
of HIV/AIDS
Solution :
Stigma (attitude) can be de ned as a discrediting attribute that
is used to separate the aected persons or groups apart from the normalized orders, or an act of identifying, labeling or attributing undesirable qualities targeted towards those who are perceived as being shamefully dierent and deviant from the social ideal . Discrimination (act) is an action or treatment based on the stigma, sanction, harassment, scapegoat and violence based on infection or association with HIV/AIDS .
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Revision questions or guidelines 1. Using appropriate examples discuss the rights of people living with HIV/AIDs at the work place. 2. During Volutary Conselling and Testing explain how the health worker should conduct him/herself to ensure the rights of the person visiting that clinic are observed. 3. Sex education is a right for every youth.
Discuss in detail what this
entails. 4. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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LESSON 10 Implications of Hiv/Aids And International Responses to the Hiv/Aids Pandemic Learning outcomes Upon completing this topic, you should be able to know:
Impacts of HIV on individuals, families, community
Demographic impacts - population
Multi - sectoral impact (Education, Agriculture, Economy, Health, Industry and Business)
Responses of African Governments to HIV - AIDS epidemic
Strategies adopted by the Kenyan government to ght the spread of HIV/AIDS
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10.1. To the individual
Feeling of hopelessness
Self pity
Depression
Suicidal thoughts
Shame
Anger
Denial
Revenge
Fear of death
Social withdrawal - segregation of infected
Opportunistic infections
Inability to work
Reduced life expectancy
Loss of job
Lack of faith in God or religion
Poverty due to medical expenses
Disruption of persons future plans
Discrimination at work place and social stigmatization
Change of sexual behavior
Poor relationship with spouse, children and relatives
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10.2. To the family
Marital instability and breakup - lack of peace in couples
Children are deprived of parental care and support
Sense of anticipating grief
Shame to the family
Loss of bread winner
Lack of emotional support/direction
Strained nances
Burden of children to the relatives and family friends
Orphans & vulnerable children have their growth aected, reduced access to basic education & increased risk of acquiring HIV due to lack of parental guidance
10.3. To the community
Reduction of productivity
Development retardation
Expensive funerals
High hospital occupancy
Financial burden for insurance companies
Increase in number of street children
Increased infant mortality rate
Dependency ratio goes up
Increased widows, widowers & orphans
Loss of many lives (human potential)
Increased diseases which were at one time in control e.g. TB
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10.3.1. How to solve negative eects
Creation of homes for orphans
Provision of free education to orphans
Introduction of Voluntary Counseling and Testing Centers
Adoption of orphans in the community
Destigmatization
10.4. Multi - Sectoral Impacts of HIV/AIDS 10.4.1. Impact on Industry and business sector
Industry and business sector forms the basis for production and supply.
Labour is required for this production to occur
HIV/AIDS has eect on labour due to:- increased absenteeism, decreased productivity, reduced number of employees through death, loss of accumulated skills and declining morale.
Increased medical costs for business with medical schemes
Declining productivity and increased medical costs results in declining pro ts
HIV/AIDS indeed reduces the productivity of the labour force.
10.4.2. Impact on agriculture
Agriculture is the mainstay of Kenya's economy, followed by tourism sector
Lower productivity in farming areas due to illness, absenteeism, death and loss of farming skills
Less land is cultivated
Less labour - intensive crop production
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Loss of household and farm assets - this is due to diverted time of family members to taking care of the sick and attending funerals.
Less crop production
Less livestock production
Decline in agricultural income and food production and increased food insecurity
Labour productivity is reduced in commercial farming as well as subsistence farming.
10.4.3. Impact on education
Increased morbidity
Absenteeism and attrition of teachers
Reduced number of school-aged children attending school
Poor performance in classroom
These result in decline in quality of education and impose higher cost on education system.
Pupils are afraid of being taught by infected teachers
Teachers reported as dying of AIDS are not replaced
Loss of trained and experienced teachers
Interruption of teaching programs due to illnesses
Resources available to support education are diverted to meet HIV/AIDS related needs
Children from aected families absent themselves because they take care of the sick
Poor attendance and increased number of school drop outs because of aected families and death of parents.
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10.4.4. Impact on health sector
Increased demand for health services due to the number of infected persons
More health resources and workforce are diverted to HIV/AIDS treatment
Shortage for other health care needs
Half or more beds in public hospitals are occupied by HIV patients
Reduced morale of health workers because HIV patients respond poorly to treatment or die
HIV infected health workers may have low productivity and morale
Anti-Retroviral Therapy (ART) is costly
Laboratory tests to monitor patients are also costly
Costs of treating opportunistic infections and prophylaxis costs.
10.4.5. Impact on economic growth
Economic growth is dependent on sustained increase in productive capacity and real output resulting in growing national income
Labour, capital and technical progress determine economic growth
HIV/AIDS aect labour and capital investments
It aects mostly the most productive members of population thus reverses growth in labour supply
Reduces productivity of infected and aected workers
Skilled persons die of AIDS reducing economic growth
Reduced level of domestic savings and investment (crucial for capital formation) due to medical expenses.
Reduced income and increased poverty imply decreased purchasing power of households thus decreased demand for goods and services
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10.5. Responses of African Governments to HIV - AIDS epidemic 10.5.1. Formation of institution to coordinate and ght HIV pandemic The AIDS programme secretariat was established to control the HIV/AIDS under the guidance of National AIDS committee(NAC). AIDS programme secretariat was elevated to the status of a National HIV/AIDS programme (NACP) under the ministry of Health. The National HIV/AIDS programme and the National STDs control programme (NSTDCP) were merged in 1994 to form the National HIV/AIDS and STD programme (NASCOP) which assumed a stronger coordinating role, especially of NGO's and religious groups.
10.5.2. Declaring HIV a national disaster The government released surveillance data and hosted the rst National conference on HIV/AIDS. The minister of health rst declared HIV/AIDS a national crisis while the government and international development partners initiated social and economic impact assessments. In November 1999, the government declared HIV/AIDS a national disaster.
This was followed by the forma-
tion and establishment of a National HIV/AIDS Control Council (NACC).The launch of the Kenya National HIV/AIDS plan in December 2000 was the advent of a new phase of bold war against the HIV/AIDS disaster.
10.5.3. Some of the strategies adopted by the Kenyan government to ght the spread of HIV/AIDS Kenya war on HIV/AIDS took a new dimension on 1st December 2003 following the launch of constituency AIDS control committees (CACC) by his Excellency President Mwai Kibaki. The launching was done during the worlds AIDS day commemoration at KICC. -The o cial launch of the National HIV/AIDS Behavior change communication strategy phase one campaign was also done the same day by the President. The strategy focuses on supporting people who are at a risk of contracting AIDS by providing accurate information through a range of media outlets.
Pamoja Tuangamize Ukimwi was selected as a
campaign slogan. In March 2004, the President launched the country total war on HIV/AIDS and formed a cabinet committee which He chairs. The committees' approach
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lies in mobilizing communities in every corner of the country to eectively ght the AIDS pandemic. The committee discussions revealed the need to include care for those orphaned by AIDS and the provision of drugs for those infected. Some of the strategies adopted by the Kenyan government to ght the spread of HIV/AIDS includes: 1. Public educational campaigns: The government through its state owned media has set up sensitization programme to try and educate the public on the dangers of the disease and also advise them to stay healthy without contracting the disease. This is done through plays; poetry and reality show programs where HIV/AIDS individuals take the opportunity to air their views and encourage others to take measures to avoid contracting the disease.
The government has also gone step ahead in creating
awareness on AIDS prevention using other channels. This includes the use of billboards, posters, public lectures, pamphlets, performing AIDS groups etc. The government has also through its o cials advocated the need to sensitize people through community barazas where government o cials get the chance to give out the much needed information on the prevention of AIDS. 2. HIV/AIDS seminars and workshops: These are opened to anybody willing to attend and they are aimed at strengthening prevention activities. Through these seminars and workshops, people are educated and enlightened by professionals on the ways of contracting the virus and the consequences o0f the disease. People are encouraged to raise questions which are answered frankly and elaborated. These are also supplemented by lms concerning HIV/AIDS and STDs. 3. Mainstreamed HIV/AIDS lessons in formal education system: HIV/AIDS has become a core unit that is studied in primary schools, secondary schools, middle level colleges and universities. Students gain knowledge on the mode of transmission, prevention and control. This has helped in the reduction of spread of HIV since the most sexually active Kenyans, the youths are taught about the dangers of casual behaviors and unprotected sexual intercourse.
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4. Destigmatization campaigns: The government of Kenya through education has helped in reducing stigmatization as many people now takes this as any other disease.
This has helped to remove stigma label on
those infected and hence are no neglected. This has encouraged free talk about AIDS and thus created awareness amongst Kenyans. 5. Free distribution of condoms: The government has taken the responsibility of distributing condoms free of charge.
These are distributed in
hospitals, during rallies on anti-HIV/AIDS campaign. The government encourages correct and consistent use of latex condoms during sexual intercourse. In this regard the government has zero rated tax on condoms and other preventive devices to ensure that its citizen can all have access to all available preventive measures. 6. Provision of treatment to HIV/AIDS patients: The government plays a role in availing treatment to HIV/AIDS patients. It provides free or subsidizes ARV drugs and other health services to people suering from HIV/AIDS. The government has taken the initiative to help prevent mother to child transmission. HIV positive mothers are given antiretroviral drugs during pregnancy and delivery.
This includes AZT which
helps in the reduction of the viral load. HIV positive mothers are also encouraged to undertake caesarian section instead of normal delivery. The government has also encouraged HIV positive mothers neither to donate breast milk to milk banks nor to express their breast milk to be bottle fed to their babies. 7. Provision of VCT centers all over the country: The government has established and opened VCT centers all over the country. VCT services are oered free of charge in most government health facilities. This has enabled most Kenyans to know their HIV status and through guidance and counseling, they have been taught on how to live positively for those aected and how to stay negative for those who are HIV negative. In VCT centers clients are taught about contracting, transmission, prevention and control. 8. Discouragement of detrimental socio-cultural practice: The government
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in conjunction with NGO's is trying to ght against socio-cultural practices that have become deadly with the advent of HIV/AIDS. They have been at the forefront of trying to eradicate such practices which includes FGM, circumcision done the traditional way, wife inheritance and early marriages. 9. Gender advocacy: The government is also advocating for gender equality and thus is teaching women on their basic rights and more so not to be sexually abused. This has empowered women and exposed them to the current world where they are recognized and respected equally as men. The government has enhanced laws against violence on women and other vulnerable groups in the society including HIV AIDS individuals to protect them from victimization. Tough laws have been enacted for imprisonment of anyone involved in rape case.
This has gone way in
reducing the spread of HIV/AIDS. 10. Poverty eradication: The government has been at the forefront of trying to eradicate poverty. It has started constituency development fund through which constituencies throughout the country receive fund from the central government and channel them to projects that help elevate the living standards of the local by creating income-generating activities. The government has also permitted formation and operations of NGO are that help people at grass root ght poverty. Some of these NGO's cater for vulnerable groups in the society.
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Exercise 12.
Revision Questions
Describe programs initiated by public health o cials to protect and improve the health of the community
Example
.
Discuss factors that have contributed to the high prevalence of
HIV/AIDS in Sub-Saharan Africa
Solution :
Premarital sex - sex before marriage, involves both fornication and
adultery.
Extra marital sex - involves having sex besides the matrimonial
spouse. Corporal adornment - of body parts which involves piercing of some body parts such as ear, nose, tattooing portions of the body etc. Cohabitation - trial marriage.
Sex for ritual purposes - these arise from the belief in the
powers of an external force, usually in the form of a spirit which can befall a person if some prescribed traditional rituals are not carried out.
Festival
seasons - during certain occasions such as Christmas, valentine day etc, there is a strong behavior towards sexual involvement. Sex for expediency - this is a relationship for the purpose of material gain of one kind of another.
Sex
for livelihood - this means commercial sex work, and involves exchange sex for money. Prostitution is the old name given to this kind of activity. Sexual orientation (Homo sexual and lesbianism) - these kinds of sexual orientation have emerged in urban centers even though they are conducted clandestinely and are strongly disproved.
Resistance to condom use - the use of condom
is a new norm in sexual union among African. It is culturally unknown and the suggestion of its use suggests sign of mistrust.
Drug and alcohol use
and abuse - use of hard drugs and alcohol predisposes those involved to risky sexual behavior in the context of HIV/AIDS. Internet and pornography - these are stimulating sexually to the mind and individuals especially the youngster may be tempted to copy and put into practice what they view thus becoming vulnerable to contract HIV/AIDS. Lack of recreational facilities - due to over development in urban centers, there is no longer space for playgrounds and other recreational facilities. The youth become idle and to reduce idleness they engage in risky behaviors that predisposes them to HIV/AIDS infection. Social stigma - because of this, HIV positive individual hide their status and behave normally while they go on infecting other people. Male and female circumcision - the same knife is used repeatedly without sterilization this leading to risk of blood contamination wit HIV. Polygamy - this practice is resilient in a number
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of communities. Given the evidence that many sexual partner increases one chances of being exposed to HIV, polygamy and extramarital relationships which are culturally tolerated play a part in the spread of HIV/AIDS. Spouse inheritance - this is a cultural practice which promotes the exchange of sexual partners after death in a family. In its formal sense it involves marrying o the surviving partner to a relative of the deceased. Given the fact that most cases of HIV transmission are as a result of heterosexual relationships and that AIDS as the cause of death is usually not disclosed to the relatives, inheritance of spouses has pose high risk of exchanging the HIV virus, thus feeling the HIV pandemic.
Cultural taboos - people attribute HIV/AIDS to witchcraft or a
curse arising from violating some cultural taboos. Most people tend to believe that HIV/AIDS does not exist.
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Revision questions or guidelines 1. The eect of HIV epidemic has prompted the Kenyan Government ti initiate various programs to reduce the spread of HIV among its citizens. Discuss this statement. 2. Discuss the impact of HIV on education 3. Anything else you would like to suggest
References and Additional Reading Materials 1. Maranga R. O, Muya S. M and Ogila K. O (2008) Fundamentals of HIV/AIDS Education. Signon Publishers. 2. Barry D. S. (1999) AIDS and HIV in Perspectives.
CPU. ISBN-13:
9780521627665 3. Ellison G. Parker M., Camphpbell C (2003) Learning from HIV and AIDS. Cambridge CPU.ISBN-13: 9780521709286. 4. Shavitri Ramaiah (2008) HIV/AIDS; Health solutions. Sterling Publishers Ltd. ISBN-9788120733305.
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Solutions to Exercises Exercise 1.
The vaccine used in the program then was discovered in the
stores of the original place that developed it. This was subsequently analyzed. It was announced that no trace had been found of either HIV or chimpanzee SIV. A second analysis con rmed that only macaque monkey kidney cells, which cannot be infected with SIV or HIV, were used to make Chat and not chimpanzee's as earlier suggested. While this is just one phial of many, most have taken its existence to mean that the OPV vaccine theory is not possible. The fact that the OPV theory accounts for just one (group M) of several dierent groups of HIV also suggests that transferal must have happened in other ways too. The nal element that suggests that the OPV theory is not credible as the sole method of transmission is the argument that HIV existed in humans before the vaccine trials were ever carried out.
Exercise 2.
Exercise 1
HIV is the human immunode ciency virus that causes AIDS
(acquired immunode ciency syndrome). When HIV infects someone, the virus enters the body and begins to multiply and attack immune cells that normally protect us from disease. It's only when someone with HIV begins to infections and illnesses that they're diagnosed with AIDS.
Exercise 3.
Exercise 2
Fertility myth - Common belief that one engage in sex to enhance
fertility in future. This not true. People have to multiply to ll the earth, a literal translation of a biblical command but people are supposed to multiply in spiritual sense. This is a corruption of the bible. Health Myth - abstaining from sex leads to sickness and madness, nobody has ever fallen sick or become mad for not engaging in sexual intercourse. Having a venereal disease is considered a badge of honor that con rms manhood. Venereal diseases confers no honor to any man. Venereal disease is cured if the man has sex with a virgin. This is not true.
On the contrary the Venereal disease suerer will transmit the
disease to the virgin. Special food and exercise will make the penis grow big. This is not true. Whatever that is good for other body parts is also good for sex organs.
Men have stronger sexual urges than women.
believed to be boundless and irrepressible.
Men sex drive is
This is not true.
Sexual urge is
equal in both the sexes. It is generally said that Africans are promiscuous This is not true. Promiscuity is not necessary an African trait has other races have
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promiscuous people too. A man cannot be satis ed by one woman. This not true. One can't get pregnant during the rst sex intercourse. Common believe that there is a grace period between the rst sexual encounter and getting pregnant - like the payment schedule on credit card.
This one isn't true.
One can't get pregnant during unprotected sex if the man pulls out before he ejaculates. This is not true. Some small amounts of sperm containing semen may be deposited in the vagina before ejaculation. Other remain in the urethra after ejaculation and can fertilize an ova. A woman is not considered to be a female if she cannot conceive a child.The femininity of a person is not judged by the ability to conceive a child.
There are other criteria.
Common belief
that virginity brings problems during birth. This is not true. Imparting sex education to youngsters will lead them to promiscuity. Educating the young on sex and sexual behaviour helps them to develop a healthy and positive attitude towards sexuality .
Exercise 4.
Exercise 3
The immune system is responsible for body defense against attack
from pathogens. It is made up of white blood cells which include granulocytes such as neutrophils and basophils, and agranulocytes such as monocytes and lymphocytes. T-helper lymphocytes have a CD4+ marker that the HIV uses for entry into the cell and replicates. T-helper lymphocytes are important in immune regulation because when they are activated they recruit other immune cell involved in immune responses. HIV uses the CD4+ cells to replicate and produce more viral particles. CD4 are killed and destroyed as viral production progresses.
Cytotoxic T-lymphocytes with CD8+ marker target any virally
infected CD4+ cells and kills them. Macrophages which have a CD4+ marker too act as reservoir and are also killed by cytotoxic. As virtually infected cells are killed by cytotoxic T-lymphocytes and more of the CD4+ cells destroyed as a result of viral replication, their numbers goes down. The immune system is depleted of these crucial cells involved in body defense and becomes vulnerable to attack by opportunistic pathogens.
Exercise 4
Exercise 5. Entry in the CD4 + - Binding of GP 120 to CD molecule allows it to bind to co-receptor causing fusion of viral and cell membrane leading to entry of virus into cell.
Reverse transcription - Conversion of viral RNA
into viral DNA under the in uence of reverse transcriptase in the cytoplasm.
Integration - Viral DNA moved into cell nucleus where it is integrated with 137
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host cell chromosome under the in uence of intergrase.
Transcription - Pro-
duction of new viral mRNA molecules for production of viral RNA involving
Translation - Viral mRNA is transported to the cytoplasm to produce viral structural proteins under the in uence of HIV Proteins. Assembly and budding - Newly made HIV core proteins enzymes and genome RNA gather inside cell and they bud o. Maturation - The core of the virus host cell enzymes.
is immature and therefore un-infectious protease breaks the long protein chains causing viral particles.
Exercise 6.
Exercise 5
Primary HIV infection - This is the initial stage where one
obtains the virus through the various modes of transmission. Window period - This stage of infection lasts for a few weeks to about 3 months and is often accompanied by a short u-like illness or no signs. HIV cannot be detected in blood screening although HIV is present in blood & the blood in not 100% free of HIV. During this time a person can still transmit the virus to another person. It's the most crucial stage. Sero conversion - This is the development of the anti-bodies.
Immune system begins to respond to HIV by producing
HIV antibodies and cytotoxic lymphocytes. If an HIV antibody test is done before seroconversion is complete then it may not be positive. In this stage a person may have u like illnesses, fever, fatigue, sore throat, joint pains & lymphadenopathy.
Some will not experience any illnesses at this stage.
Clinical asymptomatic HIV infection/ Latent phase - The presence of HIV without major symptoms. Although there may be swollen glands. The level of HIV in the peripheral blood drops to very low levels but people remain infectious and HIV antibodies are detectable in the blood, so antibody tests will show a positive result. HIV is not dormant during this stage, but is very active in the lymph nodes. Large amounts of T helper cells are infected and die and a large amount of virus is produced. This period can last for many years (5 15 years).
Symptomatic HIV infection/AIDS Related Complex (ARC)
phase - Over time the immune system loses the struggle to contain HIV due to the following main reasons: The lymph nodes and tissues become damaged or 'burnt out' because of the years of activity; HIV mutates and becomes more pathogenic, i.e. stronger and more varied, leading to more T helper cell destruction; The body fails to keep up with replacing the T helper cells that are lost. It varies between people & depends on a length of factors. Progression
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of HIV to AIDS - As the immune system becomes more and more damaged the illnesses that present become more and more severe leading eventually to an AIDS diagnosis. It's the most advanced stage of HIV infection. At this time when CD4 cell count has gone down below 200CD4 cells/ml, HIV develops to one or more severe opportunistic infections or cancer.
Exercise 6
Exercise 7. The Enzyme-Linked Immunosorbent Assay
(ELISA) -
Identi es antibodies directed speci cally against HIV. ELISA test does not establish a diagnosis of AIDS, rather it indicates that the person has been exposed to or infected with HIV. People whose blood contains antibodies for HIV are said to be sero positive.
HIV antibodies do not reach detectable
levels in the blood for one to three months.
Window period is the time
during which antibody detection using Elisa is negative. In some cases it may take even 6 months for the antibody levels to get high enough for detection. The
Western blot assay
is another test that can identify HIV antigens and
is used to con rm sero positivity as identi ed by the ELISA. This is a method that detects very low antigen levels such that one may test HIV negative by ELISA but test positive through western blot.
Babies born of HIV mother
have antibodies to HIV that were passed on during pregnancy through the placenta. However these antibodies diminish with time such that by 15 months the child may test negative. Use of Western, blot con rms presence of HIV antigen and this rules out whether babies are positive because of HIV itself or because of maternal antibodies.
PCR is also used to detect HIV in high-risk
seronegative people before the development of antibodies, to con rm a positive ELISA, to screen neonates, and to determine the exact strain of virus that is present.
CD4+Cell count - Once a patient is diagnosed positive the extent of
damage to the immune system is determined by CD4+ cell count (T-helper cell count). The number of CD4 cells present is a direct indicator of the immune system's ability to ght o opportunistic infections. The test to measure CD4 cells requires a sample of blood to be taken and measurement is made of the number of CD4 cells in a cubic milliliter of blood and will give a picture of the health of the immune system-whether it is improving or declining. The CD4 count of a person who is not infected with HIV may lie anywhere between 500 and 1200.A drop in an HIV positive persons CD4 count usually occurs over a number of years.
A CD4 count between 500 and 200 indicate that
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SZL2111 HIV/AIDs
some damage to the immune system has occurred and a count below 350 or rapid decline is an indication that one should consider anti-HIV treatment.
Measuring viral load
- Measuring viral load is essential to determine how
active the viral replication is if one is taking anti-HIV medication, then it is also a direct indicator of how successful it is in suppressing viral replication. The viral load test requires the collection of a blood sample and estimates the number of HIV particles in the sample by looking for HIV genes. The level of viral load is generally seen as a good indicator of whether to start ant-HIV treatment. An undetectable viral load is an indication that both the risk of developing AIDS and the risk of developing drug resistance has been reduced. A high viral load is an indication of high levels of HIV in body uids while undetectable viral load indicates a reduction in levels of HIV in these uids but the risk of transmitting the virus is still present.
Exercise 8.
Exercise 7
VCT has taken a central role in enlightening and guidance of
HIV/AIDS disease. Involve testing and availing the results to people in minutes. Before testing the people are prepared rst for both positive and negative results before allowed to know their status. Importance of knowing one's HIV status includes: Preventing the uninfected person from contracting the disease.
Enhancing abstinence for the infected helps in controlling the disease
through self awareness and putting up ways on how to abstain or get involved in safe sex. Counseling also helps in ensuring reduced spread of the virus by those people who have been infected but had not shown symptoms. Counseling infected people, majority of who have lost hope, helps in ensuring positive living. Help to reduce the revenge attitude for those innocently infected and may opt to die with many or commit suicide. Counseling enables the public who includes the relatives of the infected to stop stigmatizing those infected to be able to live normal lives knowing that someone cares for them. Testing also helps the government to keep statistics on the prevalence of the disease hence policy development or strategic planning. Prevention involves tackling the most important modes of transmission. sexual transmission.
Exercise 9.
Discuss brie y how to prevent Exercise 8
Early and eective treatment of STIs decreases the amount of
HIV in genital secretions and reduces the risk of its spread to other sexual partners. Early treatment also reduces the risk of contracting HIV from infected
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SZL2111 HIV/AIDs
partners. Furthermore, early diagnosis and treatment of STIs are important because they can prevent serious complications, such as infertility, ectopic pregnancy, genital cancer, blinding eye disease, and major nervous system infections in infants, that can occur as a result of an untreated STI. Exercise 9
Exercise 10.
There is a treatment called post-exposure prophylaxis (PEP)
for HIV. PEP is a month-long course of drugs that may prevent a person from becoming infected with HIV if they begin treatment within three days of exposure to HIV. If you may have been exposed, contact a health service as soon as possible for treatment. See the `Further Information' section at the end of this booklet for service details for PEP.
Exercise 11.
Exercise 10
Men still dictate matters regarding sex - for example, when to
have sexual intercourse irrespective of whether a woman wants it or not. Also use of condom relies on the man.
Girls have been taught to leave decision
making on sex matters to males whose needs and demands are expected to dominate. Male predominance often comes with intolerance for predatory and violent sexuality - this carries double standards whereby women are blamed or thrown out for in delity whether real or suspected while men are allowed to have multiple sexual partners. Biological makeup and reproductive anatomy of the female body makes her to be more vulnerable to contract HIV than men - sex takes place inside the body of the woman and the female genitalia is prone to tears and wear. These tears and wears and/or sores provide entry route for the virus. The female reproductive system is also in direct and longer contact with the male semen deposited during sexual intercourse. If the semen has HIV, then it becomes easier for her to contract the virus. Poverty failure to respect the human rights of girls in terms of equal access to school, training, employment opportunities etc. reinforces their economic dependence on men. A woman who is in a stable relationship and is economically dependent on her husband cannot aord to jeopardize his support even when she suspects that he is HIV positive. If she insists on a condom use she is accused of being unfaithful or the man reacts violently. Prostitution-a lot of women go into prostitution as a way of income generating activity.
A lot of them
end up acquiring HIV/AIDS. For some women, prostitution is a choice while others are forced by circumstances into it to exchange sex for basic necessities
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of life for themselves and their children. Cultural practices-a number of cultural practices have increased the vulnerability of women to contracting HIV. These include wife inheritance, polygamy, early marriages and resistance to condom use. Social evils - they include rape, sodomy, homosexuality, premarital, extramarital sex, and drug and alcohol abuse.
Ignorance - majority of
women are poorly educated and lack information on their bodies, HIV/AIDS and other sexually transmitted diseases. They are therefore unable to protect themselves.
Exercise 12.
Exercise 11 Vaccination - This is the process of making the body resistant
to a speci c disease by using a vaccine Vaccination programs protect people against disease.When small outbreaks of infectious disease threaten to grow into epidemics, public health o cials may initiate new vaccination programs. Rural and Urban Health Clinics - Public health agencies operate local clinics that provide free or reduced-cost medical services to individuals, especially infants and children, pregnant and nursing women, people with drug abuse problems, physical disabilities, and other conditions.
Public health clinics
routinely screen patients for a number of infectious diseases Each clinic tracks the incidence of certain communicable diseases in its area, and reports this information to national and international public health o ces. Disease Tracking and Epidemiology - Threats to public health concerns change over time and epidemiologists and other o cials continuously evaluate epidemiological trends to determine how best to meet future public health needs. Epidemiologists and other public health o cials attempt to break the chain of disease transmission by notifying people who may be at risk for contracting an infectious disease Public health o cials ensure that infected people complete treatment programs, so that the diseases are completely eliminated and the patients are no longer carriers of the infection. Sanitation and Pollution Control Disease-causing organisms are often transmitted through contaminated drinking water.
The single most eective way to limit water-borne diseases
is to ensure that drinking water is clean and not contaminated by sewage. I In many parts of the world, public health o cials establish sewage disposal and solid waste disposal systems, and regularly test water supplies to ensure they are safe. Environmental pollution is another preventable cause of disease and disability, and in most countries public health o cials address the adverse
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health eects of air pollution and water pollution. Public health o cials may work in conjunction with pollution control organizations to establish and enforce pollution limits and advise the general population when pollution levels exceed safe limits.
Medical Research Cadres of doctors and scientists work
in laboratories around the world to establish new ways to prevent, diagnose, treat, and cure disease and disability. Scientists and doctors employed by the government conduct some biomedical research in public health facilities to nd better ways to protect human health. Public Education Campaigns Many diseases are preventable through healthy living, and a primary public health goal is to educate the general public about how to prevent noninfectious diseases.. Health promotion encourages people to take advantage of early diagnostic tests that can make the outcome of disease more favourable e.g. early breast cancer detection .
Exercise 12
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