Just to be pedantic, genocide requires one to deliberately kill off a large group of people.
Fortunately something like small pox has been eradicated and the worst diseases that lead to epidemics have been largely contained, so it is unlikely he was in contact with them.
Something simple like a cold virus even an isolated group should fight off fine. They still have immune systems, and probably fairly robust as they have to deal with a lot more bacteria and parasites than the average person does today.
