1. Malawi Epidemiology and Intervention Research Unit, Lilongwe, Malawi
2. Department of population health, London School of Hygiene and Tropical Medicine, London, United Kingdom
3. Department of Epidemiology and Biostatistics, Kilimanjaro Christian Medical University College, Moshi, Tanzania
4. Mwanza Intervention Trials Unit, Mwanza, United Republic of Tanzania
5. Ifakara Health Institute, Ifakara, United Republic of Tanzania
6. Africa Health Research Institute, KwaZulu-Natal, South Africa
7. Department of HIV and AIDS, Malawi Ministry of Health, Lilongwe, Malawi
8. University of Kwa-Zulu Natal, Durban, South Africa