1. Pathogens

2. Definition
An organism or virus that causes disease in its host.

3. Example # 1
Influenza is caused by viruses

4. Example # 2
Tuberculosis is caused by bacteria

5. Example # 3 Thrush is caused by fungi
aka yeast infection (candida albicans)

6. Example # 4 Malaria is caused by protozoa P. falciparum, P. vivax,
P. ovale, and
P. malariae
Anopheles mosquito

7. Example # 5
Schistosomiasis (bilharzia) is caused by flatworms

8. Example # 6 Hookworm is caused by roundworms
Ancylostoma duodenale and Necator americanus.

9. Transmission of Pathogens
Contact
Touch, pathogen enters through skin
Cuts
Skin cut or punctured by infected object
Droplets
Droplets containing pathogens are sneezed out by infected person and breathed in by another
Food or Water
Enter body through soft gut wall
Sexual Intercourse
Enter body through soft mucus membranes of penis or vagina
Insects
Suck blood out of infected person and transmit pathogens to another

10. Tuberculosis—A Bacterial Disease
Cause
Mycobacterium tuberculosis
Rod-shaped bacterium
Malnutrition, overcrowding, stress increase chances of infection

11. Tuberculosis Transmission Droplets
A rare form of TB can pass from cow’s milk to humans

12. Tuberculosis Effects Lungs infected with TB bacteria
Phagocytes move to lungs and engulf bacteria
Bacteria survive and breed inside phagocyte
Tubercles form in lungs—small, rounded swellings containing infected phagocytes
First infection is usually not severe
Re-infection results in chronic TB which gradually destroys the lung tissue
Fever, loss of appetite, weight loss, persistent cough, coughing up blood
Infection can spread to lymph nodes, bones, and gut
Over 3 million deaths/year world-wide caused by TB

15. The next slide is kind of gross

18. Antibiotics Used to treat bacterial diseases
Bacterial cells are very different than human cells so bacteria can be targeted and killed without harming human cells
Viruses use human cells as hosts. If a virus was targeted with an “antibiotic,” human cells would be harmed.