1. Social Aspects of Health Programme, MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda
2. Social Science and Research Ethics Department, Africa Health Research Institute, KwaZulu-Natal, South Africa
3. MRC International Statistics and Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
4. Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK