1. Pathogen A disease-causing organism Harmful –Hurt host cells Physically or through a toxin (poison) Bacterial diseases –Strep throat, Pneumonia, Lyme’s disease, Bubonic plague, STD’s (many)

2. Three types of pathogens Bacterium –Examples of diseases: meningitis, strep throat Viruses –Ex. Diseases Hepatitis A, B, C Fungus –Ex. Disease; Athlete’s foot

3. Disease Transmission Exposed – when you come in contact with a pathogen Infected – when the pathogen enters the body AND causes disease

4. What does infection depend on? Dose – amount of organisms that enter the body Virulence – strength of the organism Host resistance –ability of your immune system to fight infection

5. Non-living pathogens Viruses – –Genes (DNA or RNA) in a protective protein shell -- Ebola, measles, polio, cancers) Prions – –infectious protein particles -- transmissible spongiform encephalopathies (TSEs) -- Creutzfeld-Jakob disease (kuru), bovine spongiform encephalopathy (BSE or mad cow disease) Parasitic DNA -- transposons -- mobile genetic elements -- heritable disorders -- hemophilia, severe combined immunodeficiency, porphyria, cancer

6. Transmitting Diseases Air Water Sexual Personal Contact Animals

7. Airborne Anthrax Tuberculosis

8. Water/Foodborne diseases Foodborne: Salmonella Listeria Waterborne Cholera

9. Sexual Contact Chlamydia Gonorrhea Herpes Simplex HIV/AIDS HPV Syphilis

10. Bloodborne Pathogens HBV (hepatitis B) AIDs Hepatitis (A, B, C) Syphilis Malaria Brucellosis

11. Personal Contact Common colds Typhoid Shigella Norovirus

12. Rocky Mountain Spotted Fever (ticks) West Nile Virus (mosquitos) Lyme Disease (ticks) Malaria (mosquitos) Bubonic Plague (transmitted from rats to humans via fleas) Insect Borne

13. So…what to do????

14. Personal Contact and Hygiene

15. Controlling Diseases Sanitation and Hygiene –Washing –Filtering or boiling water –Chlorine Antibiotics –Used to kill bacteria that have caused (or could cause) infection. Can be preventive.

16. Controlling Diseases - Vaccines Used to PREVENT disease –Produces immunity (some temporary, some permanent Causes body to produce antibodies MMR –99% effective with booster Varicella Zoster –Not as effective Smallpox (variola) Polio (poliovirus)

17. Controlling Disease - Antibiotics Used to TREAT disease –Interfere with cell walls –Stop growth Cannot stop viruses like the rhinovirus –Usually given if 2ndary bacterial infections occur (like bronchitis, pneumonia, etc)

18. Controlling Disease – antiviral drugs Some prevent cell entry Some target protein or protein sequences unique to the virus Some prevent polymerase binding –HIV –Herpes –Hepatitis B –Influenza