1. Department of Pediatrics and Child Health, Red Cross War Memorial Hospital, University of Cape Town, Cape Town, South Africa
2. SA MRC unit on child and adolescent Health, Red Cross War Memorial Hospital, University of Cape Town, Cape Town, South Africa
3. Division of Cardiology, Department of Medicine, Groote Schuur Hospital and Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
4. Division of Pediatric Cardiology, Red Cross War Memorial Children’s Hospital, Rondebosch, Cape Town, South Africa
5. Division of Epidemiology and Biostatistics, School of Public Health and Family Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
6. Department of Pediatrics, Division of Infectious Diseases, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA