Emerging and RE-Emerging Infectious Disease In Medieval times disease was seen as punishment from God. AIDS???????

Germ Theory ( Bacterial Pathogens) 1- Organism always present in sick animals. 2- Organism Can be isolated and grown in a pure culture. 3-When culture is introduced to health animal it must cause sickness. 4-Organism re-isolated from healthy animal must be same as original animal.

Bacterial Diseases DiseaseYear DiscoveredScientist anthrax1876Kotch gonorrhea1879Neisser tuberculosis1882Kotch plague1894Kitasato,Yersin Whooping cough1906Bordet,Gengoe

Other pathogens Virus- (made of Protein and nucleic acid) require a host cell to reproduce.-ex. Yellow Fever Fungi- ex.- athletes foot, yeast infections. Parasites- Live at the expense of other organisms – protozoa ex. malaria and helminths(from the round worm or flat worm phyla) ex. Hook worms Prions????? Unusual proteins may be a pathogen.

Prevention and treatment Survivors of disease become immune Chinese “valorization ” using dried material from Small Pox sores.( risk of severe infection) Edward Jenner uses cow pox in immunize against Small Pox( much safer) Louis Pasteur- develops immunization against anthrax( bacterial Pathogen) and Rabies( viral pathogen) he also discovers that heating or “pasteurizing” liquids kills potentially harmful bacteria.

Antibacterial Drugs ( Antibiotics) Kill microbes without killing the patient. Alexander Fleming – Penicillin produced from mold – kills staphylococcal bacteria Antibiotics flourished after WWII and many infectious diseases were eradicated. Anti-viral meds are more difficult because viruses reproduce within the cells of the host. Most meds would harm the healthy cells while trying to kill the virus.

Emerging Diseases New diseased not seen before- Escherichia coli strain0157:H7- sickness and death in the 1990’s Ebola hemorrhagic fever % Fatality rate. Appeared in the Congo in AIDS- Emerges simultaneously in US and Africa in 1980’s What do you think might explain the emergence of these “new pathogens”???

Re- Emerging diseases Diseases that were previously controlled are making a “comeback”. WHY???? Les strict enforcement of immunization programs and other public health programs, Antibiotic resistant pathogens have evolved. Tuberculosis and Malaria – major killers world wide Staphylococcus aureus- causes Bacterial Pneumonia and is immune to ALL known antibiotics Could we be heading for another “pandemic era”???