1. Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine , London , United Kingdom
2. AIDS and TB Department, Ministry of Health and Child Care , Harare , Zimbabwe
3. The Health Research Unit, Biomedical Research and Training Institute , Harare , Zimbabwe
4. Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine , London , United Kingdom
5. Social Science Unit, Zambart , Lusaka , Zambia
6. Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine , London , United Kingdom
7. Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich , Munich , Germany