Frequent and Widespread Simian Retrovirus Infection in Persons Exposed to Nonhuman Primates
Abstract
The recognition that AIDS originated as a zoonosis heightens concerns associated with human infection with simian retroviruses (SRs) endemic in nonhuman primates (NHPs), including simian immunodeficiency virus (SIV), simian type D retrovirus (SRV), simian T-cell lymphotropic virus (STLV), and simian foamy virus (SFV).1,6,7 Although few SR infections in persons occupationally exposed to NHPs have been reported, the prevalence and significance of these zoonoses are not fully defined.3-5 In addition, infections with SRs in persons who hunt, butcher, or keep NHPs as pets have not been documented. Consenting participants (n=418) from 15 North American research centers and zoos provided a serum sample for serologic testing for SIV, SRV, STLV, and SFV. Matching plasma and peripheral blood lymphocyte (PBLs) from an anonymous survey of primate hunters in Cameroon (n=1,099) were also available for SFV testing. Testing of sera from NHP workers identified no STLV infection. Two sera from persons with known SIV infection were positive for SIV.3 Sera from 2 persons were positive for SRV (0.48%) but PCR testing and virus isolation were negative in both cases.4 In contrast, sera from 14 workers (3.35%; 12 males, 2 females) and 10 Cameroonians (0.9%; 7 males, 3 females) were found to be SFV positive using validated serologic assays.2 SFV integrase sequences were PCR amplified from the PBL DNA from 13 workers and 3 Cameroonians. Phylogenetic analysis showed SFV infection originating from African green monkey (n=1), baboons (n=4), and chimpanzees (n=8) in the occupationally exposed persons and from mandrill (n=1), gorilla (n=1), and DeBrazza’s guenon (n=1) in the primate hunters.8,9 Our study documents SFV infection originating from six NHP species in persons exposed to NHPs and suggests that such zoonoses are more frequent, widespread, and contemporary than previously thought. These findings highlight the importance of defining the public health significance of these emerging zoonotic infections.
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