Providing leadership and excellence in health facility development
BASIC EPIDEMIOLOGY IN INFECTION PREVENTION AND CONTROL
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Basic Epidemiology of Healthcare Associated Infections and Infection Prevention and Control IPC HEALS Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Epidemiology • Study of the distribution or occurrence of disease or event in a given population or geographical area including the factors that contributed to this: – Attempts to investigate and relate causal factors to a disease or event of interest – Analyzes association of one event (risk or causal factors) with another later event (outcome or disease)
• Epidemiology applied to infection control involves a systematic identification of major problems and calculations of rates in order to prioritize the efforts of infection control team and obtain basic data needed for decision making and wise policy development Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Learning Outcomes 1. Know the concept of healthcare associated infection (HAI); 2. Understand the transmission of infections in the healthcare environments; 3. Know the general principles on how these HAIs can be reduced. Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
What are healthcare-associated infections (HAIs)? • Infection is the state or condition in which the body or part of the body is invaded by pathogenic agents (bacteria, viruses, fungi, parasites, and others) which under favorable condition multiplies and produces adverse affects on the susceptible host.
• Healthcare associated infections (HAIs) are infections that occur in susceptible patients caused by microbes/agents acquired within or any healthcare facility (HCF) during delivery of health services. These infections are not present on admission, acquired 48 hours after confinement, or developed after discharge or consultation from any healthcare facility. Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
• The common sites of HAIs are the urinary tract, respiratory tract, gastrointestinal tract, skin and soft tissues, bloodstreams, surgical sites and others. • Healthcare associated infections used to be called “nosocomial infection” which reflected their original association with hospitalized patients. • In the current era of managed care, hospital epidemiology has expanded and it became relevant beyond the acute care hospital and now includes all settings where healthcare is delivered. Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Why are we concerned with HAI? • HAIs are significant public health problem because they occur frequently, cause morbidity and mortality, and results in substantial economic burden to patients, healthcare workers and the health systems. • HAIs occur worldwide and affect all countries irrespective of their degree of development. The prevalence rate of HAI is 3.5%-12% (average 7.5%) in developed countries and 5.7%-19.1% in low and middle countries. The incidence rate in ICU is 51% in developed countries, 4.4% to 88.9% and 3 times more for low and middle income countries. Nearly 3 out of 4 HAI in acute care healthcare facilities are the result of one of the devices.
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
• Cost of HAI goes beyond the direct patient hospitalization costs and includes: o o o o o o o o o o
Patient extended or repeated hospitalization cost Income loss Disfigurement Disability Pain and suffering Death Loss of revenue Liability insurance Malpractice Reputation
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Why do HAIs occur in a healthcare facility (HCF)? In any healthcare facility, the three elements (Figure 4) required to establish or complete the chain of infection are present: • The microbial agent in patient care or reservoir • The susceptible host • A means of transmission Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Figure 1-1. The THREE elements required for the HAI to occur
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
1. What are the microbial agents? Where do they come from in a healthcare facility setting? Sources of agents causing HAI •
Infectious are usually outside the body of the patient or from EXGENOUS sources – Hands of healthcare worker is the MOST IMPORTANT SOURCE which can be reduced – Instruments/Endoscopes – Catheters – Respiratory equipment – Transfusion lines – Intravenous systems – Linen – Air Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
• Infections can also come from the patient’s own microbial flora or called ENDOGENOUS source – Oropharynx – Respiratory – Gastrointestinal – Skin
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Table 1-1. Microorganisms frequently causing HAI Gram Negative Rods Escherichia coli
Gram Positive Cocci Staphylococcus aureus
Others Fungi candida sp.
Klebsiella sp.
Staphylococcus epidermis
Aspergillus sp.
Enterococci
Acinetobacter sp.
Mycobacterium tuberculosis
Enterobacter sp.
Anaerobes
Pseudomonas aeruginosa
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Protozoans
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
2.Who are the susceptible hosts? All hospitalized patients can have HAIs but those with the following factors listed below are at increased risk for HAI: Age – the very young and very old Immune deficiency states • Malignancy • Therapeutic measures • Immunosuppression with steroids and other drugs Instrumentation/Diagnostic procedures Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Surgery/Operations/Invasive procedures Invasive devices • Catheter • Foreign body • Respiratory equipment • Chronic underlying disease • Diabetes • COPD • Chronic renal disease (Hemodialysis) Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
3. How do the microbial agents reach the susceptible hosts and cause HAI? How are they transmitted? Means of transmission of infection Contact Transmission: actual transfer the microbial agent by physical touching of surfaces
– Direct-contact – Direct body surface-to-body surface contact and – Physical transfer of microorganisms between a susceptible host and an infected or colonized person
– Indirect-contact – Contact of a susceptible host with an intermediate object, usually inanimate, such as contaminated instruments, needles, or dressings, surfaces or contaminated hands or gloves Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Droplet Transmission: Droplets are large particles (larger than 5μm in size) generated to the air from persons with respiratory and other infections during coughing, sneezing, and talking or during procedures such as suctioning and bronchoscopy – Because droplets are big and heavy, they fall to the ground after a distance of 3 feet or less; thus, transmission can only occur if there is close contact between the source and the susceptible hosts – Transmission may occur if the infectious droplets are deposited on the susceptible host’s conjunctivae, nasal mucosa, or mouth or inhaled. Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Airborne Transmission – Airborne transfer of small-particle residue (5μm or smaller) of evaporated droplets containing microorganisms (TB, Measles, Varicella) – These tiny droplets remain suspended in the air for long time periods – Dispersed by air currents – Transmission occurs if the infectious droplets are inhaled by a susceptible host within the same room or over a longer distance Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Vertor-borne Transmission – Mechanical vector-borne transmission – Agent does not multiply or undergo physiological change in the vector (transfusion, intravenous fluid, dengue, leptospirosis) – Biological vector-borne transmission – Agent is modified within the host before being transmitted (malaria, schistosimiasis) Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Table 1-2. Mode of Transmission of HAI MODE OF TRANSMISSION Contact
Droplet Airborne Vehicles
PROCESS Physical contact with infectious material Inhalation or mucosal exposure of larger infectious droplets Inhalation of very small infectious droplets Through inanimate materials like food, water, Intravenous fluid, medications
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
EXAMPLES OF INFECTIONS Multi-drug resistant organisms, most skin infections Mumps, rubella, pneumonia, menigococcemia Tuberculosis, measles, chickenpox Infectious diarrheas, bacteremias Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
The chain of transmission is a very important concept and must become very clear to healthcare workers. It can be shown through various diagrams such as in Figures 1-1, 1-2 and 1-3. The figures which follow below makes it easy to understand where prevention of infection may be done to reduce risk for HAI.
Figure 1-2. The Transmission Components required for transmissionBoosting to successfully Republic of the Philippinesof Infection showing HtheFThree D B occur Department of Health Universal Health Coverage HEALTH FACILITY DEVELOPMENT BUREAU
Providing leadership and excellence in health facility development
On the other hand, the figure below is attractive to use as depicts the non-ending circle of events creating the concept of a chain of infections.
H F D B
Republic of the Philippines Boosting Figure 1-3. of The Chain of Infection in an unending cycle unless the factors leading to infections are controlled or the chain is “broken” Department Health Universal Health Coverage HEALTH FACILITY DEVELOPMENT BUREAU
Providing leadership and excellence in health facility development
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Republic of the Philippines Department of Health
H F D B
Figure 1-4. Breaking the chain of infection HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Thus, with Figure 1-4, it is easier to think of IPC as a structured program put in place to address the components of the “Chain of Infection” so that the Chain is broken. PREVENTION AND CONTROL OF HAI are directed to the various links of the chain (breaking the chain) and include: 1. Elimination or containment of agents 2. Interrupting the transmission of infections 3. Protecting the host against infection and disease Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
It has been shown that approximately 30% of HAI can be prevented by applying interventions that have been proven effective and are of low cost. More recently there has been a paradigm shift on understanding of HAIs. Whereas in the past HAIs were perceived to be inevitable consequences of hospitalization, specially prolonged hospitalization, today HAI is considered an undesirable outcome and always potentially preventable. An effective IPC program in a healthcare facility can minimize transmission of infectious agents and development of HAI during delivery of healthcare service. Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Key messages: Basic Epidemiology of HAIs • HAIs cause undesirable outcomes including morbidity and complications, additional medical cost and extended length of hospital stay and worst, loss of patients’ lives. • HAIs occur in health facilities because the ingredients which allow the chain of infection prevail. • The links of this chain can be destroyed through an evidence-based and well-implemented IPC program. • Every HAI must be seen now as an undesirable event and every effort to prevent it must be done. Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Reference: Rosenthal VD. Epidemiology and control of healthcareacquired infections in limited-resource settings (chapter 18). In: Jarvis WR, editor. Bennett & Brachman’s hospital infections. 6th ed. Philadelphia: Wolters Kluwer. Lippincott & Wilkins; 2014. p. 230-75
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage
Providing leadership and excellence in health facility development
Republic of the Philippines Department of Health
H F D B HEALTH FACILITY DEVELOPMENT BUREAU
Boosting Universal Health Coverage