1. Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe, Uganda
2. Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
3. Nuffield Department of Population Health, Wellcome Centre for Ethics and Humanities (Ethox), University of Oxford, Oxford, UK
4. Navrongo Health Research Centre, Navrongo, Ghana
5. Department of Health Promotion & Education, School of Public Health, University of Zambia, Lusaka, Zambia