1. Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg
2. National Health Laboratory Service, Johannesburg
3. Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
4. Department of Global Health, Boston University School of Public Health, Massachusetts
5. Department of Epidemiology, Boston University School of Public Health, Massachusetts
6. Southern Africa Labour and Development Research Unit, University of Cape Town, South Africa
7. World Health Organization, HIV/AIDS, Geneva, Switzerland