1. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
2. Centre for the AIDS Programme of Research in South Africa (CAPRISA), Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa;
3. SAMRC-CAPRISA HIV-TB Pathogenesis and Treatment Research Unit, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa;
4. Perinatal HIV Research Unit, University of the Witwatersrand, Johannesburg, South Africa;
5. University of Zimbabwe Clinical Trials Research Centre, Harare, Zimbabwe;
6. Makerere University-Johns Hopkins University (MU-JHU) Research Collaboration, Kampala, Uganda;
7. Centre for the AIDS Programme of Research in South Africa (CAPRISA), Umlazi Clinical Research Site, University of Kwazulu-Natal, Durban, South Africa;
8. University of Kwazulu-Natal, Department of Family Medicine, Durban, South Africa;
9. Johns Hopkins Research Project, Kamuzu University of Health Sciences, Blantyre, Malawi;
10. University of North Carolina Project-Malawi, Lilongwe, Malawi;
11. Department of Obstetrics and Gynecology, University of North Carolina, Chapel-Hill, NC;
12. Center for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston MA; and
13. Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, USA.