Leendertz SA, Junglen S, Hedemann C, Goffe AS, Calvignac S, Boesch C, Leendertz FH (2010): High prevalence, co-infection rate and genetic diversity of retroviruses in wild red colobus monkeys (Piliocolobus badius badius) in Tai National Park, Côte d'Ivoire
J. Virol. 84 (15): 7427-7436. Epub 19 May, 10.1128/JVI.00697-10.

Simian retroviruses are precursors of all human retroviral pathogens. However, little is known about the prevalence and co-infection rates as well as the genetic diversity of major retroviruses - simian immunodeficiency viruses (SIV), simian T-cell Lymphotrophic viruses type 1 (STLV-1) and simian foamy viruses (SFV) - in wild populations of non-human primates. Such information would contribute to the understanding of the natural history of retroviruses in various host species. Here we estimate these parameters for wild West African red colobus monkeys (Piliocolobus badius badius) in the Taï National Park, Côte d'Ivoire. We collected samples from a total of 54 red colobus monkeys; blood and/or internal organs from 22 monkeys, and additionally, muscle and other tissue samples from further 32 monkeys. PCR analyses revealed a high prevalence of SIV, STLV-1 and SFV in this population: 82%, 50% and 86%, respectively. Forty-five percent of the monkeys were co-infected with all three viruses while another 32% were co-infected with SIV in combination with either STLV or SFV. As expected, phylogenetic analyses showed a host-specific pattern for SIV and SFV strains. In contrast, STLV-1 strains appeared to be distributed in genetically distinct and distant clades, which are unique to the Taï forest and include strains previously described from wild chimpanzees in the same area. The high prevalence of all three retroviral infections in the P. b. badius, represents a source of infection to chimpanzees, and possibly humans, who hunt them.