1. Human to Human Transmission of Infectious Diseases

2. Basics of Disease Control
Control the environment
Control the host
Control the vector
Why does this make diseases with human hosts the most legally problematic?

3. Factors that Affect Human Susceptibility to Infectious Diseases
Genetics
Immunologic system function
Environmental factors

4. Genetics Sickle cell trait Evolutionary adaption to malaria
Damaging as sickle cell disease
HIV
Probably leprosy
Others we do not understand

5. Environmental Factors
Factors that affect immunologic function
Nutritional status
Stress
What does this tell us about developing countries and refugee camps?
Factors that increase exposure/cause stress
Crowded housing
Poor sanitation
Poor working conditions

6. Breaker boys in coal mine - Lewis Hine

7. Immunosuppressive Drugs
A post 1960s phenomena
Steroids
Asthma
Arthritis
Feel good docs
Chemotherapeutic agents
Anti-rejection agents for transplants
Impact on infection dynamics

8. Transmission Dynamics
How hard is it to catch the disease? (Contact effectiveness)
Measles
Leprosy (Hanson's Disease)
How susceptible is the population?
Immunity?
Environmental factors?
How many people are infectious carriers?
How well do the carriers mix with the general population?
Are there high risk subgroups?

9. Tuberculosis #1 Killer, probably for all time
Mycobacterium tuberculosis
Related to leprosy
Very hard to kill
Can lay dormant for decades
Can affect any organ system
Dangerous when it is pulmonary - you cough up the bugs and spread them

10. Transmission Person to person Takes significant exposure
Medicated by fomites
Animal hosts
Milk
Still a risk for raw milk

11. Detection TB skin testing Looking for antibody reaction
Not so good in immunosuppressed people
Conversion
You are infected
You may not have actively growing bugs
Confirmation
HIV test
X-ray
Treatment - 1 year of isoniazid

12. Treatment of Active TB
Active - pulmonary infection that can spread infectious material
Treatment
Takes time to make the patient non-infectious
Much longer or never for drug resistant
Long course for cure
Incomplete treatment
drug resistant
worst case - pan drug resistance

13. Legal Issues for TB Detection Treatment
Treatment failure/drug resistance