An article on the Discovery Channel website says that HIV's ancestry has been traced to wild chimps. Apparently, the process for proving this involved tracking wild chimps and collecting their virus-laden feces (and you thought your job was bad). The article goes on to say that:
"Presumably, someone in rural Cameroon was bitten by a chimp or cut while butchering one and became infected with the SIV virus."
Uh huh. That's one theory. I've got another one. I won't say what it is, but it rhymes with "limp trucker".