1 Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch, South Africa; Tygerberg Academic Hospital, Cape Town 7505, South Africa. Electronic address: hrabie@sun.ac.za.
2 Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch, South Africa; Tygerberg Academic Hospital, Cape Town 7505, South Africa.
3 Division of Medical Virology, National Health Laboratory Services, Stellenbosch University, Stellenbosch, South Africa.