Quotes from David Quammen

One of the things that's particularly nefarious about Ebola is that it continues to live in a dead person for some period of time after death. A person who's been dead for a day or two may still be seething with Ebola virus.

You can't take a knife on a plane anymore, but you can get on carrying a virus.

We're shaking loose viruses and dislodging them from their natural ecological limitations, places where they aren't very abundant and have competition, even within a single animal. We introduce them into a new, rich habitat called the human population, where they can flourish more abundantly and cause more trouble.

Viruses have to live somewhere. They can only replicate in living creatures. So, when the Ebola virus disappears between outbreaks, it has to be living in some reservoir host, presumably some species of animal.