1 School of Public Health and Family Medicine, University of Cape Town, Cape Town 7925, South Africa. Electronic address: morna.cornell@uct.ac.za.
2 Faculty of Infectious and Tropical Diseases, Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, UK.
3 School of Public Health and Family Medicine, University of Cape Town, Cape Town 7925, South Africa; Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA.
4 Desmond Tutu HIV Centre, University of Cape Town, Cape Town 7925, South Africa; Research Unit, Foundation for Professional Development, East London, South Africa.
5 Division of Infectious Diseases, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.