AIDS: Etiology, Diagnosis, Treatment, and Prevention. Second Edition.
AIDS was first described as a new and distinct clinical entity in 1981.
The first cases were recognized because of unusual clustering of
diseases such as Kaposi's sarcoma and Pneumocystis pneumonia in young
homosexual men. The history of AIDS is summarized, including studies of
the infectious etiology of AIDS, the origins of human retroviruses, the
origins of HIV-1, the HIV-related retroviruses of monkeys, and HIV-2.
Although simian immunodeficiency virus (SIV) and HIV-2 clearly are
highly related, and each is more than 50% related to HIV-1, none of
these viruses is very closely related to other retroviruses. More
distant relatives include lentiviruses such as equine infectious anemia
and visna, which share only a small amount of homology with the HIVs,
and HTLV-I and II, which share even less genomic homology but more
biologic characteristics, such as T4 lymphocyte tropism. It seems less
likely that SIV in African green monkeys was the immediate precursor of
HIV-1, but highly likely that it did give rise to HIV-2. A more logical
hypothesis might be that HIV-1 moved into humans from a precursor virus
in another species yet to be identified. Similarly, the postulated
evolutionary virus progenitor that gave rise to both SIV and HIV-1 has
not been identified. (59 Refs)
Acquired Immunodeficiency Syndrome/*MICROBIOLOGY/TRANSMISSION Animal
Haplorhini Human HIV-1/*PATHOGENICITY HIV-2/*PATHOGENICITY Monkey
Diseases/MICROBIOLOGY Retroviridae Infections/MICROBIOLOGY/VETERINARY
Risk Factors SIV/PATHOGENICITY MONOGRAPH REVIEW REVIEW, TUTORIAL