Main article: Origin of AIDS

The earliest known positive identification of the HIV-1 virus comes from the Congo in 1959 and 1960 though genetic studies indicate that it passed into the human population from chimpanzees around fifty years earlier.[11] A recent study states that a strain of HIV-1 probably moved from Africa to Haiti and then entered the United States around 1969.[22]
The HIV virus descends from the related simian immunodeficiency virus (SIV), which infects apes and monkeys in Africa.
A more controversial theory known as the OPV AIDS hypothesis suggests that the AIDS epidemic was inadvertently started in the late 1950s in the Belgian Congo by Hilary Koprowski's research into a poliomyelitis vaccine.[29][30]
Wikipedia http://en.wikipedia.org/wiki/AIDS