1. Division of Infectious Diseases, Department of Medicine, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas and College of Physicians and Surgeons, Columbia University Medical Center, New York, New York.
2. AIDS Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa.
3. International Center for AIDS Programs, Mailman School of Public Health, Columbia University, New York, New York.
4. Empilweni Services and Research Unit, Rahima Moosa Mothers and Children Hospital, University of the Witwatersrand, Johannesburg, South Africa.
5. Harriet Shezi Clinic, Chris Hani Baragwanath Hospital, Enhancing Childhood HIV Outcomes (ECHO), University of the Witwatersrand, Johannesburg, South Africa.
6. Department of Molecular Medicine and Haematology, University of the Witwatersrand, and National Health Laboratory Service, Johannesburg, South Africa.
7. Gertrude H. Sergievsky Center, College of Physicians and Surgeons, and Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York.