I watched a doc recently on YouTube about the "Patient Zero" myth. One of the things that proves it's a myth is the fact that the people coming forward to say they caught it from him would actually have had to get it from him 8 years earlier.

My point being, it was kicking peoples' asses because it's something that's asymptomatic for a long time, and then it's symptomatic through other infections. So nobody knew anything was wrong while it was spreading, then all those people got sick at once.