If a disease affects only a human and not an animal, then it would be difficult to fulfill Koch's postulate number ________.
A) 4
B) 3
C) 2
D) 1
E) 8

Question

Quizplus · Accepted Answer

Koch's postulate number 3 requires that the microorganism be isolated from the diseased host and grown in pure culture, then reintroduced into a healthy, susceptible host and cause the same disease. If a disease affects only humans and not animals, it would be difficult to find a suitable animal host to fulfill this postulate.

If a Disease Affects Only a Human and Not an Animal