Alex Shoumatoff, "In Search of the Source of AIDS." It was the longest study of the disease I'd seen at the time, and was comprehensive in its examination of the evidence. I don't have the exact date, but the Vanity Fair was volume 51 (the citation peters out after that in Google, and the actual page is through a full-text journal I don't have access to, but it was in about 1986 of 1987). The essay was apparently reprinted in his 1990 collection African Madness .

The Amazon review is mixed, and I think this reviewer doesn't like Shoumatoff in general. I remember reading his Dian Fosse article also (I subscribed to Vanity Fair back in the 1980s, before I had kids so I still had time to read it!) and thinking it was very good. I've posted a new review over at Amazon to rebut, somewhat, the first review.

SRS