1. Wits RHI (Wits Reproductive Health and HIV Institute), University of the Witwatersrand, Faculty of Health Sciences, Johannesburg, South Africa;
2. Department of Global Health and Development, London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom;
3. Mwanza Intervention Trials Unit (MITU), National Institute for Medical Research, Mwanza, Tanzania;
4. International Center for Research on Women (ICRW), Washington, DC, USA