HIV was discovered by Barré-Sinoussi, Montagnier, andcolleagues at the Institut Pasteur, Paris, in 1983 and given thename lymphadenopathy associated virus (LAV). In 1984Popovic, Gallo, and co-workers described the development ofcell lines permanently and productively infected with the virus.In line with two previously described retroviruses, HTLV-I andHTLV-II, they designated this virus HTLV-III. Other virusisolates from patients with AIDS and AIDS-related disease inAmerica, Europe and Central Africa have proved to be all thesame virus, now referred to as HIV-1. Eight subtypes of HIV-1,alphabetically designated, have so far been described.Around 1985 another human retrovirus, different from HIV-1, was recognised in patients from West Africa. This virus,referred to by the Paris investigators as LAV-2 and morerecently as HIV-2, is also associated with human AIDS andAIDS-related disease. It is closely related to the simianretrovirus, SIV, carried by healthy African green monkeys, andthe cause of an AIDS-like disease in captive rhesus monkeys.Though potentially important worldwide, HIV-2 infectionsremain uncommon outside West Africa and they have proved farless virulent than HIV-1 infections.
