This research study was approved by the Faculty of
Health Sciences Higher Degrees Committee (HDC49/02-
2011) and Academic Ethics Committee (AEC51/02-2011),
who report to the National Health Research Ethics Council
in South Africa. Participation in this study was subject to
informed and signed consent from the parents or guardians,
as well as the child’s assent. Participants were free to
withdraw from the study at any stage.