[SIV as a source of HIV. On the origin of human immunodeficiency viruses from non-human primates]

Abstract

It is assumed that HIV, the human immunodeficiency virus, started its spread after the Second World War. Molecular analysis of the genome of various HIV-1 types has shown that this virus can be divided into the groups M, N, and O and that these genome sequences fit perfectly to the genomes found in SIV of chimpanzees (SIVcpz) living in the area of West and Central Africa. SIVcpz is nonpathogenic for chimpanzees indicating that the virus and host have adapted for a long period. HIV-2 genome sequences converge with SIV sequences of sooty mangabey monkeys from West Africa (SIVsm), covering the subtypes A to G from HIV-2. SIVsm is nonpathogenic for mangabey monkeys. All available data indicate that HIV-1 and HIV-2 have been introduced into humans at least several times. Since SIVcpz and SIVs from other monkeys are recombinant viruses, it cannot be excluded that a new recombinant SIV might again enter the human population and initiate a new epidemic.