Question: how do you acctually find a virus that has been found many years ago? when you find the old viruses, do you telll the public and what sort of comment so you get?

Katy Brown answered on 21 Jun 2013:

The viruses we study were around millions of years ago, but they have now degraded, so they can’t cause any harm any more. This means we don’t need to alert the government or the public when we find one. If we found a virus which was unknown but still active we would have to, but that is unlikely.

We find the viruses because circulating viruses of the type I study sometimes accidentally end up as a permanent part of the DNA of the animal they infect. They deteriorate so they don’t damage the animal, but they still look similar to modern viruses. I take the DNA sequences of viruses we already know about, and compare them a bit at a time to the DNA of different animals. If I find a piece of animal DNA which looks like it came from a virus I analyse it to see what it is.