1. Neonatal Team, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, P.O. Box 17049, Congella, Durban 4013, South Africa
2. Department of Paediatrics, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, P.O. Box 17049, Congella, Durban 4013, South Africa
3. Infectious Diseases Team, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, P.O. Box 17049, Congella, Durban 4013, South Africa