1. Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine (MRC/UVRI and LSHTM), Uganda Research Unit, Entebbe, Uganda
2. Global Health and Development Department, London School of Hygiene and Tropical Medicine, London, UK
3. Centre for Sexual Health and HIV/AIDS Research, Harare, Zimbabwe
4. International Public Health Department, Liverpool School of Tropical Medicine, Liverpool, UK
5. School of Public Health, University of Sydney, Sydney, Australia