Molecular epidemiology of simian immunodeficiency virus infection in wild-living gorillas
Neel, C.;Etienne, L.;Li, Y.;Takehisa, J.;Rudicell, R. S.;Bass, I. N.;Moudindo, J.;Mebenga, A.;Esteban, A.;Van Heuverswyn, F.;Liegeois, F.;Kranzusch, P. J.;Walsh, P. D.;Sanz, C. M.;Morgan, D. B.;Ndjango, J. B. N.;Plantier, J. C.;Locatelli, S.;Gonder, M. K.;Leendertz, F. H.;Boesch, C.;Todd, A.;Delaporte, E.;Mpoudi-Ngole, E.;Hahn, B. H.;Peeters, M.
Journal of Virology
Chimpanzees and gorillas are the only nonhuman primates known to harbor viruses closely related to HIV-1. Phylogenetic analyses showed that gorillas acquired the simian immunodeficiency virus SIVgor from chimpanzees, and viruses from the SIVcpz/SIVgor lineage have been transmitted to humans on at least four occasions, leading to HIV-1 groups M, N, O, and P. To determine the geographic distribution, prevalence, and species association of SIVgor, we conducted a comprehensive molecular epidemiological survey of wild gorillas in Central Africa. Gorilla fecal samples were collected in the range of western lowland gorillas (n = 2,367) and eastern Grauer gorillas (n = 183) and tested for SIVgor antibodies and nucleic acids. SIVgor antibody-positive samples were identified at 2 sites in Cameroon, with no evidence of infection at 19 other sites, including 3 in the range of the Eastern gorillas. In Cameroon, based on DNA and microsatellite analyses of a subset of samples, we estimated the prevalence of SIVgor to be 1.6% (range, 0% to 4.6%), which is significantly lower than the prevalence of SIVcpzPtt in chimpanzees (5.9%; range, 0% to 32%). All newly identified SIVgor strains formed a monophyletic lineage within the SIVcpz radiation, closely related to HIV-1 groups O and P, and clustered according to their field site of origin. At one site, there was evidence for intergroup transmission and a high intragroup prevalence. These isolated hot spots of SIVgor-infected gorilla communities could serve as a source for human infection. The overall low prevalence and sporadic distribution of SIVgor could suggest a decline of SIVgor in wild populations, but it cannot be excluded that SIVgor is still more prevalent in other parts of the geographical range of gorillas. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

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