1. AFROStrep Research Group, Department of Medicine, Faculty of Health Sciences, University of Cape Town & Groote Schuur Hospital, Cape Town, South Africa
2. Health Systems Research Unit, South African Medical Research Council, Cape Town, South Africa
3. Children's National Health System, Division of Cardiology, Washington, DC, USA
4. Division of Infectious Diseases, Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA