1. Department of Internal Medicine, King Edward VIII Hospital, Nelson R. Mandela School of Medicine, University of Kwa-Zulu Natal, South Africa
2. Department of Internal Medicine, Chris Hani Baragwanath Academic Hospital, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
3. Department of Internal Medicine, Klerksdorp-Tshepong Hospital Complex, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
4. Department of Internal Medicine, Helen Joseph Hospital, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
5. Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa