E-mail Abstract Author Session Search Abstracts Program

Session 59 Poster Presentations Viral Genetic Diversity Session Day and Time: Thursday 1:30 - 3:30 pm Room: Hall A

501
SIVcpz Prevalence and Genetic Diversity in Wild Communities of Eastern Chimpanzees
M. Santiago*¹, M. Lukasik ², S. Kamenya ², Y. Li ¹, F. Bibollet-Ruche ¹, D. Goldenberg³, M. Muller ⁴, M. Emery⁴, D. Watts ³, R. Wrangham ⁴, A. Pusey ⁵, D. Collins ², J. Goodall ⁶, G. Shaw ⁷, B. Hahn ^1
1Univ of Alabama at Birmingham; ²Gombe Stream Res Ctr, Kigoma, Tanzania; ³Yale Univ, New Haven, CT; ⁴Harvard Univ, Cambridge, MA; ⁵Univ of Minnesota, St Paul; ⁶Jane Goodall Inst, Silver Springs, MD; and ⁷Howard Hughes Med Inst, Univ of Alabama at Birmingham, AL

Background: Current knowledge of the prevalence and genetic diversity of simian immunodeficiency virus (SIVcpz) infection of wild chimpanzees (Pan troglodytes) is incomplete since only few isolates have been characterized; yet this information is critical for understanding the origins of HIV-1 and the circumstances leading to the current AIDS pandemic.
Methods: Testing 214 urine and 218 fecal samples for virus specific antibodies and vRNA, respectively, we screened > 145 wild chimpanzees from 5 different communities in east Africa for evidence of SIVcpz infection. Results: Analysis of 80 urine samples from 31 chimpanzees from the Kanyawara community in Kibale National Park (Uganda) failed to detect SIVcpz specific antibodies. Similarly, analysis of 45 urine and 58 fecal samples from 39 chimpanzees from the neighboring Ngogo community failed to yield evidence of SIVcpz infection. By contrast, analysis of 160 fecal and 89 urine samples from > 75 apes in Gombe National Park (Tanzania) identified 7 SIVcpz infected chimpanzees: 2 in the northern Mitumba, 2 in the central Kasekela, and 3 in the (non-habituated) southern Bwavi community. Two (2) of these were diagnosed by detection of urine antibodies, while 5 others contained SIVcpz vRNA in their feces. Sequence analysis of RT-PCR fragments revealed that the 5 Gombe strains represented divergent viruses that formed a monophyletic lineage within the SIVcpzPts radiation. None of the sequenced SIVcpz strains were sufficiently closely related to represent a transmission pair. Finally, the Gombe viruses did not group according to their community of origin.
Conclusions: SIVcpz infection is endemic in Gombe, but possible absent from Kibale National Park. Moreover, the prevalence of SIVcpz in Gombe is low (< 10%) and far lower than prevalence values reported for SIV infection in other small nonhuman primates. It is possible that virus transmission in chimpanzees is inherently less efficient than in smaller primates, and this coupled with declining chimpanzee population size, habitat fragmentation, or other ecological perturbations, have contributed to low SIVcpz prevalence rates-or even virus extinction-in certain communities. Additional field studies are needed to understand more completely the epidemiology and natural history of this medically important family of viruses.

---