1. School of Public Health, University of the Western Cape, Private Bag x17, Bellville, 7535 Republic of South Africa
2. Makerere University, School of Medicine, P O Box 7062, Kampala, Uganda
3. Faculty of Social Sciences, University of Dar es Salaam, P O Box 35091, Dar Es Salaam, Tanzania
4. School of Medicine, Kabale University, P O Box 317, Kabale, Uganda
5. Makerere University, School of Public Health, P O Box 7072, Kampala, Uganda