1 Faculty of Medicine and Health Sciences, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch, South Africa; Faculty of Health Sciences, Centre for Infectious Disease Epidemiology and Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.
2 Division of Paediatric Infectious Diseases, Department of Paediatrics, University of KwaZulu-Natal , Durban , South Africa.
3 Faculty of Medicine and Health Sciences, Division of Paediatric Infectious Diseases and Family Clinical Research Unit (FAM-CRU), Department of Paediatrics and Child Health, Stellenbosch University , Stellenbosch , South Africa.