1 Division of Epidemiology and Biostatistics, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.
2 Non-Communicable Diseases Research (NCDR) Division of the Wits Health Consortium, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
3 Division of Medical Oncology, Department of Internal Medicine, Faculty of Health Sciences, School of Clinical Medicine, University of the Witwatersrand, Johannesburg, South Africa.
4 Division of Infectious Diseases, Department of Medicine, RWJ Barnabas Health, NBIMC, Newark, New Jersey.
5 Private practitioner, Johannesburg, South Africa.