1. Wits Reproductive Health & HIV Institute, School of Clinical Medicine, University of the Witwatersrand, Cape Town, South Africa
2. National Health Laboratory Service, Mycobacteriology Referral Laboratory & Department of Clinical Microbiology & Infectious Diseases, University of the Witwatersrand, Cape Town, South Africa
3. Harriet Shezi Children's Clinic, Department of Paediatrics, Chris Hani Baragwanath Hospital, Faculty of Health Sciences, University of the Witwatersrand, Cape Town, South Africa