Wild Mandrillus sphinx are carriers of two types of lentivirus

Mandrillus sphinx, a large primate living in Cameroon and Gabon and belongi ng to the Papionini tribe, was reported to be infected by a simian immunode ficiency virus (SIV) (SIVmndGBI) as early as 1988, Here, we have identified a second, highly divergent SIVmnd (designated SIVmnd-2), Genomic organizat ion differs between the two viral types; SIVmnd-2 has the additional vpx ge ne, Like other SIVs naturally infecting the Papionini tribe (SIVsm and SIVr cm) and in contrast to the other SIVmnd type there designated SIVmnd-1), wh ich is more closely related to SIVs infecting I'hoest (Cercopithecus Ihoest i Ihoesti) and sun-tailed (Cercopithecus Ihoesti solatus) monkeys. Importan tly, our epidemiological studies indicate a high prevalence of both types o f SIVmnd; all 10 sexually mature wild-living monkeys and 3 out of 17 wild-b orn juveniles tested were infected. The geographic distribution of SIVmnd s eems to be distinct for the two types: SIVmnd-1 viruses were exclusively id entified in mandrills from central and southern Gabon, whereas SIVmnd-2 vir uses were identified in monkeys from northern and western Gabon, as well as in Cameroon, SIVmnd-2 full-length sequence analysis, together with analysi s of partial sequences from SIVmnd-1 and SIVmnd-2 from wild-born or wild-li ving mandrills, shows that the gag and pal regions of SIVmnd-2 are closest to those of SIVrcm, isolated from red-capped mangabeys (Cercocebus torquatu s), while the env gene is closest to that of SIVmnd-1, pol and env sequence analyses of SIV from a related Papionini species, the drill (Mandrillus le ucophaeus), shows a closer relationship of SIVdrl to SIVmnd-2 than to SIVmn d-1, Epidemiological surveys of human immunodeficiency virus revealed a cas e in Cameroon of a human infected by a virus serologically related to SIVmn d, raising the possibility that mandrills represent a viral reservoir for h umans similar to sooty mangabeys in Western Africa and chimpanzees in Centr al Africa.