1. Department of Clinical Research, School of Hygiene & Tropical Medicine, London, United Kingdom.
2. The Aurum Institute, Johannesburg, South Africa.
3. Collaborative Programme for AIDS Research in South Africa, University of KwaZulu-Natal, Durban, South Africa.
4. Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, London, United Kingdom.
5. Adult HIV Clinic, Chris Hani Baragwanath Hospital, Johannesburg, South Africa.
6. Anglo Platinum, Safety, Health & Environment, Johannesburg, South Africa.
7. Department of Infectious Disease Epidemiology, Faculty of Infectious and Tropical Diseases, School of Hygiene & Tropical Medicine, London, United Kingdom.