Emerging Diseases

Bio 1 lecture SDJacinto Institute of Biology, University of the Philippines, Diliman

Definition "New, re-emerging or drug resistant

infections whose incidence in humans has increased within the past two decades or whose incidence threatens to increase in the near future." [US Institute of Medicine Report, 1992]

Causative agents.. The fact that many kinds of disease are related to microorganisms was unknown until the middle of the 19th Century, by the time of Pasteur. Doctors often relied on toxic compounds like arsenic and mercury that could kill bacterial cells, but were also very harmful to the normal cells of the infected person.

We learn about the afflictions of our ancestors by studying human remains, art, and literature. Head of Pharaoh Rameses V showing eruptions strongly suggestive of smallpox

www.collphyphil.org/ emerging_dis/emdsmain.htm

Although many viral diseases remained unconquered, effective vaccines prevented some of the most frightening ones. The success of antibiotics after World War II led to the impression that bacterial infections could be easily cured.

The case of poliomyelitis in England and Wales

Another success story *January 1, 1967 WHO Intensified Smallpox Eradication Campaign Vaccination Success in 1977

"Infectious Diseases are more easily prevented and more easily cured than any other major group of disorders..." ( Harrison's Principles of Internal Medicine 10th ed., 1983). Much of the industrialized world basked in a feeling of invulnerability, assuming that heart disease and cancer were the major health problems left to conquer.

*1957-65 WHO Problems with Malaria Eradication •DDT, Chloroquin, --Malaria control abandoned by 1974 •Problem arising from the solution •DDT pollution •Mosquito resistance, •Chloroquin resistance

Today we view infectious disease with greater respect. The victories of the past are seen in perspective with the emergence of HIV/AIDS and at least 30 other new infections. Old foes (tuberculosis, rabies, malaria, and pneumonia) are evading traditional therapies and are now on the comeback. Infectious diseases are the leading cause of death in the world !!! and the third leading cause of death in the United States.

1980s = End of optimism •Resurgence of malaria + cholera + tuberculosis •AIDS ? HIV + African diseases: Ebola, Marburg + Legionnaire’s, Toxic Shock Syndrome + 36 others since 1980! Globalisation: SARS

Deadly microbes can now easily infect us due to…

Rapid population increase Urbanization Change in lifestyle

Re-emerging disease- Tuberculosis

www.chstm.man.ac.uk/.../ hs2151/lecture-8.htm

Why are they reemerging? Microbe: MDR (multi drug resistant) strains Medicine: Less effective drugs Public health: BCG vaccine (Bacillus Calmette-

Guerin) coverage down Infection: Importation by immigrants

Reemerging (Reinventing?) the bubonic plague

http://en.wikipedia.org/wiki/Black_Death

Effect of plague on population

www.biology.eku.edu/ RITCHISO/317notes3.html

Emerging diseases Influenza SARS Severe Acute Respiratory

Syndrome (Feb 2003) AIDS ( Acquired Immunodeficiency Syndrome) Hemorrhagic fever Lyme disease E. coli 0157:H7 Bird Flu

-Caused by lentivirus -Carries RNA -Attacks the immune system -Person dies of opportunistic diseases

www.chstm.man.ac.uk/.../ hs2151/lecture-8.htm

www.wramc.amedd.army.mil/ fieldmed/emerging.cfm

Ebola Reston virus caused severe illness and death in monkeys imported to research facilities in the U. S. and Italy are from the Philippines!!

www.cdc.gov/.../spb/ mnpages/dispages/ebola.htm

Sexually Transmitted Diseases-also caused by microbes  Bacterial vaginosis  Chlamydia (Chlamydia trichomatis)  Gonorrhea (bacteria Nesseria gonorrhea- in reproductive

tract, urethra of men and women, eyes, mouth, throat, anus)  Human papillomavirus (HPV) most common-types are the wart -causing and cancer –causing HPV  Pelvic inflammatory disease- (PID) secondary to other STDscan lead to serious consequences including infertility, ectopic pregnancy (a pregnancy in the fallopian tube or elsewhere outside of the womb), abscess formation, and chronic pelvic pain.  Syphilis- caused by the bacterium Treponema pallidum; called “the great imitator” because so many of the signs and symptoms are indistinguishable from those of other diseases. In 2006, 64% of the reported syphilis cases were among MSM

Syphilis patients

news.bbc.co.uk www.clinicalvirology.org

www.adhb.govt.nz

What about cancer?

Xenoestrogens and breast cancer Organochlorides suspected

xenoestrogens possibly affecting female and male population (http://www.fwhc.org/health/xeno.htm)

Biological warfare (BW) ’Employment of biological agents to

produce casualties in man or animals or damage to plants.’ Human exposure to these agents may occur through inhalation, skin (cutaneous) exposure, or ingestion of contaminated food or water. Following exposure, physical symptoms may be delayed and sometimes confused with naturally occurring illnesses. Biological warfare agents may persist in the environment and cause problems some time after their release.

History of BW BW attack took place in the Black Sea port of Kaffa

(now Feodossia, Ukraine) in 1346. Rats and their fleas carried disease to attacking Tartar soldiers. Between 1754 and 1767 when the British infiltrated smallpox-infested blankets to unsuspecting American Indians during the French and Indian war. 1932, the Japanese began experiments on human beings at ‘Unit 731’ outside Harbin, Manchuria, China. At least 11 Chinese cities were attacked with the agents of anthrax, cholera, shigellosis, salmonella, and plague, and at least 10,000 died during their gruesome experiments; reportedly dropped fleas over China and stockpile anthrax for fragmentation bombs

http://images.google.com.ph/imgres?imgurl=http://english.china.com/zh_cn/culture_history/news/11020710/20070321/imag es/14000738_2007032111154427107400.jpg&imgrefurl=http://english.china.com/zh_cn/culture_history/news/11020710/2007 0321/14000738.html&h=720&w=960&sz=139&hl=tl&start=5&um=1&tbnid=rjugboMsWSLVWM:&tbnh=111&tbnw=148&prev=/i mages%3Fq%3DUnit%2B731%26um%3D1%26hl%3Dtl%26sa%3DN

US and BW The United States started an offensive biological

warfare program at Camp Detrick (today Fort Detrick) in Frederick, Maryland in 1943. Ten years later, the defensive program began. In 1969, the U.S. had weaponized the agents causing anthrax, botulism, tularemia, brucellosis, Venezuelan equine encephalitis, and Q fever. These were soon destroyed after President Nixon unilaterally ended the U.S. offensive biological warfare program 1972 the U.S. signed the Biological Weapons Convention stating that it would never develop, produce, stockpile, acquire, or retain BW agents or the means to deliver them.

The Black Maria was the first laboratory facility built to accommodate top secret research. Scientists completed interior equipment intstallation www.detrick.army.mil/ cutting_edge/chapter07.cfm

BW in more recent history By 1991, the Iraqis had weaponized anthrax,

botulinum toxin, and aflatoxin.Fortunately, these were not used during Desert Shield or Desert Storm. The United Nations destroyed the final remains of the Iraqi offensive program in 1996. in 1995, the Aum Shinrikyo cult, that released

sarin nerve gas in a Japanese subway, was found to possess rudimentary biological weapons including anthrax, botulism, and Q fever. Use of ricin toxins, anthrax

‘Advantages’ of Biological Warfare BW agents can cause large numbers of casualties

with minimal logistical requirements. Perpetrators can escape long before BW agents cause casualties, due to the incubation periods of the agents. Weapons are easy and cheap to produce and can be used to selectively target humans, animals, or plants. The costs of conventional weapons ($2000), nuclear armaments ($800 M), and chemical agents ($600) would far outstrip the bargain-basement price of biological weapons ($1) to produce 50% casualties per square kilometer (1969 dollars).

Disadvantages of using BW agents hazards to the user, their dependence on optimal weather

conditions for effective dispersal,  their possible inactivation by solar irradiation and other climatic conditions (BW attacks would most likely occur late at night or early in the morning when agents would be less likely to undergo inactivation by ultraviolet radiation).

Diseases/agents Smallpox (Variola virus) Anthrax (Bacillus anthracis) Plague (bubonic, Yersinia pestis) Brucellosis suis from various animals, flu

like symptoms Tularemia (Francisella tularensis)-

plague like transmissible via rodents Botulism caused by potent protein neurotoxins produced by Clostridium botulinum

What are CDCs doing? Stockpiling antibiotics to treat infected

people Coordinating a nation-wide program where states share information about different diseases Creating new education tools and programs for health professionals, the public, and the media.

The End