1. Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, Torrance
2. David Geffen School of Medicine, University of California, Los Angeles
3. Wits Reproductive Health and HIV Institute, University of the Witwatersrand, Johannesburg, South Africa
4. Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
5. University of Zimbabwe-University of California, San Francisco, Collaborative Research Programme, Harare, Zimbabwe
6. Department of Epidemiology, University of Washington, Seattle
7. Department of Medicine, University of Pittsburgh
8. Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles