aDesmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa

bDivision of Paediatric Infectious Diseases, Department of Women's and Children's Health, University of Padua, Padua, Italy

cPaediatric Infectious Diseases, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa

Correspondence to Marieke M. van der Zalm, Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa. Tel: +27 21 9389764; e-mail: [email protected]