THE global pandemic could have been so different. After AIDS was recognised in the US in 1981, many cases were found in Haitians, but it was never clear how Haiti figured in the epidemic.
Now Thomas Gilbert at the University of Arizona at Tucson and colleagues have analysed HIV samples collected from five Haitians living in Miami in 1982, and their relationship to 117 HIV samples from 19 other countries. The resulting “family tree” makes it clear that a virus originating in Haiti was the ancestor of virtually all HIV outside Africa, making Haiti the “stepping stone” from Africa to…
