1. Centre for HIV and STIs, National Institute for Communicable Diseases , Private Bag X4, Sandringham, Johannesburg 2131 , South Africa
2. Department of Virology, Faculty of Health Sciences, University of the Witwatersrand , Johannesburg , South Africa
3. Right to Care , Johannesburg , South Africa
4. National Health Laboratory Services , Johannesburg , South Africa
5. Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand , Johannesburg , South Africa
6. School of Public Health, Faculty of Health Sciences, University of the Witwatersrand , Johannesburg , South Africa
7. Division of Global HIV and Tuberculosis, Center for Global Health, Centers for Disease Control and Prevention , Pretoria , South Africa
8. Department of Paediatrics and Child Health, Faculty of Health Sciences, University of the Witwatersrand , Johannesburg , South Africa
9. Division of Global HIV and Tuberculosis, Center for Global Health, Centers for Disease Control and Prevention , Atlanta, GA , USA