1. Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
2. Research Department, Medecins Sans Frontieres, Nhlangano, Swaziland
3. Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
4. MRC/UVRI Uganda Research Unit On AIDS, Entebbe, Uganda
5. The University of Sydney School of Public Health, Sydney, Australia
6. Swaziland National AIDS Programme, Ministry of Health, Mbabane, Swaziland
7. Department of Population Health, London School of Hygiene and Tropical Medicine, London, UK