Epidemiology

Question 1

What are the Henle-Kock postulates

Answer 1

1. The parasite must be present in all who have the disease;
2. The parasite can never occur in healthy persons;
3. The parasite can be isolated, cultured and capable of passing the disease to others

Question 2

What are reasons the causal relationship my fall apart?

Answer 2

Confounding bias
Measurement bias
Systemic bias