AIDS transitioned to man from monkeys and chimps, but presumably through handling and eating them, rather than through ....ing them. When I was young and foolish I got elbows deep into an anthrax carcass and was about to eat the thing, were it not for an absurd coincidence involving a vet wandering through the bush who recognized it for anthrax. I thought the subcutaneous lesions were signs of a cheetah kill!