Encyclopedia of AIDS, T.J. Hope, M. Stevenson, and D. Richman, Editors. 2014, Springer New York. p. 1-12
Human and simian immunodeficiency virus (HIV and SIV) are both Lentiviridae, a subgroup of the Retroviridae, which are characterized by the presence of regulatory genes in addition to the gag, pol, and env genes. At least 12 independent cases of SIV transmission from chimpanzees, gorillas, or sooty mangabeys (SMs) to humans have been documented. HIV-1M, the epidemic strain of HIV, was likely introduced into the human population via an SIV-infected chimpanzee around the beginning of the twentieth century. Sooty mangabey SIV (SIVsmm) gave rise to both HIV-2, which is largely restricted to West Africa, and SIVmac (Munch and Kirchhoff 2012). In contrast to natural hosts, Asian macaques are not infected with SIVmac in the wild.
Over 40 African nonhuman primate species are infected with species-specific SIVs. Infection has been extensively studied in only four of these species: African green monkeys (AGMs), sooty mangabeys, mandrills, and chimpanzees. The first three have a nonpatho …