5.00 Understand Emerging and Re-emerging Infectious Diseases

1. 5.00 Understand Emerging and Re-emerging Infectious Diseases Key Terms

2. Review: • Emerging: • 1. Have not occurred in humans before. • 2. Have occurred, but affected only a small number of people in isolated areas. • 3. Have occurred throughout history but have only recently been recognized as a distinct disease.

3. Review: • Re-emerging: • Diseases that once were major health problems globally or in a particular country and then declined but are now coming back. • Antiquity: • Since ancient times

4. Review • Endemic: • Found in a certain area, among a particular people and is ongoing, steady since antiquity. Has not declined. • Infection: Results when a pathogen invades and begins growing within a host. • Disease: Results only if and when tissue function is impaired.

5. Review: • Host: Human or animal where the infectious agent enters to reproduce and maintain itself. • Reservoir: Environment where the infectious agent survives. • Virulent: How strong is the agent; How • likely is it to cause disease. • Pathogen: Microorganism capable of causing disease.

6. New Terms: • Epidemic: A widespread outbreak. • Pandemic: An epidemic of infectious disease that has spread through human populations across a large region, for example: multiple continents, or even world wide. • Epidemiology: The study of the occurrence of disease in populations. • Asepsis: The absence of pathogens • Toxin: Poisonous to humans

7. Other Infectious Diseases: • Tetanus: A pathogenic bacteria that is one of the few with a non-living reservoir, which is the soil. • Trichinosis: A disease due to a helminth that comes from eating contaminated pork. Can be fatal due to congestive heart failure or respiratory paralysis. • Rabies: A re-emerging disease caused by direct contact. Re-emerging because of break down in public health measures.

8. Infectious Diseases: • Candida: A fungal organism that causes yeast diseases known as an opportunistic pathogen. Easily affects people who are immunocompromised. • Staphylococcus: Organism most likely to cause an opportunistic infection. • Pertussis: (Whooping cough)- Re-emerging because of refusal to vaccinate based on fears the vaccine is not safe.

9. Infectious Diseases: • SARS: Severe Acute Respiratory Syndrome • Agent: Coronavirus • Fever, Dry cough, headache, muscle aches, difficulty breathing • TX: Supportive Care • Transmission: Droplets in Air from sneezing, coughing or talking • HX: Appeared in 2002, Emerging

10. Microorganisms that cause Infectious Disease • Bacteria: Unicellular prokaryotic organisms; reproduce by growing and dividing into two cells. • Virus: Infectious agent that cannot reproduce apart from a host cell. • Fungi: Eukaryotic, reproduce by forming spores. • Protozoa: Unicellular, Eukaryote, capable of rapid and flexible movements. Acquired through contaminated food or water or a mosquito bite.

11. Microorganisms: • Helminths: Multicellular, eukaryotic invertebrates with tube like or flattened bodies. (Round worms, flat worms, nematodes, tapeworms and flukes). Unlike other microorganisms, helminths do not multiply within their host. Worms grow and produce off occurring in rodents, pigs, horses, bears, and humans, and is responsible for the disease trichinosis. It is sometimes referred to as the "pork worm" due to it being typically encountered in undercooked pork products. Trichinellaspiralis is an example.

12. Microorganisms • Prions: Infectious agent composed entirely of protein material, long incubation periods and able to induce abnormal folding of specific normal cellular proteins which leads to brain damage.