How are scientists able to track the birthplace and movements of diseases like AIDs or the Black Death, even after people are long dead?

Question

How are scientists able to track the birthplace and movements of diseases like AIDs or the Black Death, even after people are long dead?

In: 43

Answer 1

Some diseases leave marks on the skeleton, in those cases disease can be fairly accurately diagnosed in long deceased remains. In other cases like HIV the virus itself mutates rapidly which can leave a trail if you sequence enough variants, but this is not detectable long after death unless there are preserved/frozen samples.