High prevalence of simian immunodeficiency virus infection in a community of savanna chimpanzees
Authors: Jim Moore
Yingying Li
Alex K Piel
Lilian Pintea
Rebecca S Rudicell
Deborah L Moore
Jun Takehisa
Gerald H Learn
Beatrice H Hahn
Fiona Stewart
Paul M Sharp
George M Shaw
Journal: Journal of Virology (2011)
Discipline: MICROBIOLOGY
Keywords: Simian immunodeficiency virus; SIVcpz; chimpanzees; prevalence; distribution
Affiliations: Departments of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, Department of Anthropology, University of California at San Diego, La Jolla, California 92093, Leverhulme Centre for Human Evolutionary Studies, University of Cambridge, Cambridge CB2 1QH, United Kingdom, Department of Anthropology, University of Texas at San Antonio, San Antonio, Texas 78249, Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, The Jane Goodall Institute, Arlington, Virginia 22203, Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom

Abstract:  Simian immunodeficiency virus of chimpanzees (SIVcpz) has a significant negative impact on the health, reproduction, and life span of chimpanzees, yet the prevalence and distribution of this virus in wild-living populations are still only poorly understood. Here, we show that savanna chimpanzees, who live in ecologically marginal habitats at 10- to 50-fold lower population densities than forest chimpanzees, can be infected with SIVcpz at high prevalence rates. Fecal samples were collected from nonhabituated eastern chimpanzees (Pan troglodytes schweinfurthii) in the Issa Valley (n = 375) and Shangwa River (n = 6) areas of the Masito-Ugalla region in western Tanzania, genotyped to determine the number of sampled individuals, and tested for SIVcpz-specific antibodies and nucleic acids. None of 5 Shangwa River apes tested positive for SIVcpz; however, 21 of 67 Issa Valley chimpanzees were SIVcpz infected, indicating a prevalence rate of 31% (95% confidence interval, 21% to 44%). Two individuals became infected during the 14-month observation period, documenting continuing virus spread in this community. To characterize the newly identified SIVcpz strains, partial and full-length viral sequences were amplified from fecal RNA of 10 infected chimpanzees. Phylogenetic analyses showed that the Ugalla viruses formed a monophyletic lineage most closely related to viruses endemic in Gombe National Park, also located in Tanzania, indicating a connection between these now separated communities at some time in the past. These findings document that SIVcpz is more widespread in Tanzania than previously thought and that even very low-density chimpanzee populations can be infected with SIVcpz at high prevalence rates. Determining whether savanna chimpanzees, who face much more extreme environmental conditions than forest chimpanzees, are more susceptible to SIVcpz-associated morbidity and mortality will have important scientific and conservation implications. 

Retracted: No

PubPeer comments:
 Figure 2. * Red boxes: Two blot strips representing two different animals look unexpectedly similar ![file] Here is the false-color version to confirm the similarities. ![file] ,