1. Pathogens
Bacteria and Viruses

2. Pathogens Organism that causes disease Types: Examples?
Bacteria, viruses, fungi, protists
Examples?
Plasmodium  malaria
HIV  AIDS
HPV  genital warts, cervical cancer
Dermatophytes  athlete’s foot
Salmonella  food poisoning

3. How do they spread? Coughing, sneezing, and physical contact
Exchange of body fluids
Contaminated water or food
Animal vectors

4. Emerging Diseases Formerly unknown or newly evolved diseases
Ex. AIDS in the 1980’s
West Nile Virus
H1N1
Drug-resistant TB
Ebola
We often do not have a way to control them
Our bodies have little resistance to them

5. Emerging Diseases

6. Bacterial Diseases How do they cause disease? Other examples:
Destroy living cells
Directly infect cells
Indirectly – may trigger an immune response that damages cells
Releasing toxins
Poisons interfere with our cells’ activities
E.g. Botulism paralyzes muscles
Other examples:
TB, Tetanus, Lyme disease, Strep throat

7. Controlling bacterial infections
Wash surfaces/hands  washes away bacteria
Use chemicals  disinfectants
Properly store our food  refrigeration
Cook food fully  kills bacteria
Heat sterilization  e.g. surgical tools
Antibiotics  treat bacterial infections
Vaccines – prepare immune system

8. Viral Diseases How do they cause disease? Examples:
Attack and destroy specific types of cells
Can change patterns of growth and development of cells  leads to cancer
Examples:
Common cold, influenza (flu), HIV/AIDS, chicken pox, Hepatitis B, HPV

9. Controlling viral diseases
Vaccines
Good hygiene – wash hands, use Kleenex!
Avoid contact with sick individuals
Antibiotics DO NOT work against viruses
Few antiviral drugs