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Novel simian foamy virus infections from multiple monkey species in women from the Democratic Republic of Congo

William M Switzer1*, Shaohua Tang1, Steve Ahuka-Mundeke23, Anupama Shankar1, Debra L Hanson1, HaoQiang Zheng1, Ahidjo Ayouba2, Nathan D Wolfe4, Matthew LeBreton4, Cyrille F Djoko4, Ubald Tamoufe4, Amandine Esteban2, Walid Heneine1, Martine Peeters2, Linda L Wright5, Jean Jacques Muyembe-Tamfum3, Emile Okitolonda Wemakoy6, Prime Mulembakani6, Nicole A Hoff7 and Anne W Rimoin7

Author Affiliations

1 Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA

2 Institut de Recherche Pour le Développement, Montpellier, France

3 Institut National de Recherche Biomedicale, Kinshasa, Democratic Republic of Congo

4 Global Viral Forecasting Initiative, San Francisco, CA, 94104, USA

5 Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA

6 Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo

7 Department of Epidemiology, UCLA School of Public Health, University of California at Los Angeles, Los Angeles, CA, 90095, USA

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Retrovirology 2012, 9:100  doi:10.1186/1742-4690-9-100

Published: 5 December 2012

Abstract

Background

Zoonotic transmission of simian retroviruses in Central Africa is ongoing and can result in pandemic human infection. While simian foamy virus (SFV) infection was reported in primate hunters in Cameroon and Gabon, little is known about the distribution of SFV in Africa and whether human-to-human transmission and disease occur. We screened 3,334 plasmas from persons living in rural villages in central Democratic Republic of Congo (DRC) using SFV-specific EIA and Western blot (WB) tests. PCR amplification of SFV polymerase sequences from DNA extracted from buffy coats was used to measure proviral loads. Phylogenetic analysis was used to define the NHP species origin of SFV. Participants completed questionnaires to capture NHP exposure information.

Results

Sixteen (0.5%) samples were WB-positive; 12 of 16 were from women (75%, 95% confidence limits 47.6%, 92.7%). Sequence analysis detected SFV in three women originating from Angolan colobus or red-tailed monkeys; both monkeys are hunted frequently in DRC. NHP exposure varied and infected women lived in distant villages suggesting a wide and potentially diverse distribution of SFV infections across DRC. Plasmas from 22 contacts of 8 WB-positive participants were all WB negative suggesting no secondary viral transmission. Proviral loads in the three women ranged from 14 – 1,755 copies/105 cells.

Conclusions

Our study documents SFV infection in rural DRC for the first time and identifies infections with novel SFV variants from Colobus and red-tailed monkeys. Unlike previous studies, women were not at lower risk for SFV infection in our population, providing opportunities for spread of SFV both horizontally and vertically. However, limited testing of close contacts of WB-positive persons did not identify human-to-human transmission. Combined with the broad behavioral risk and distribution of NHPs across DRC, our results suggest that SFV infection may have a wider geographic distribution within DRC. These results also reinforce the potential for an increased SFV prevalence throughout the forested regions of Africa where humans and simians co-exist. Our finding of endemic foci of SFV infection in DRC will facilitate longitudinal studies to determine the potential for person-to-person transmissibility and pathogenicity of these zoonotic retroviral infections.

Keywords:
Simian foamy virus; Retrovirus; Zoonosis; Africa; Women; Transmission; Public health; Emerging