1. Division of Medical Microbiology, Department of Pathology, University of Cape Town , Cape Town , South Africa
2. Wellcome Centre for Infectious Disease Research, and Institute of Infectious Disease and Molecular Medicine, University of Cape Town , Cape Town , South Africa
3. Department of Paediatrics and Child Health and South African Medical Research Council Unit on Child and Adolescent Health, University of Cape Town and Red Cross War Memorial Children’s Hospital , Cape Town , South Africa
4. Division of Infection and Immunity, School of Biomedical Sciences, University of Western Australia , Perth , Australia