Funding for this research was provided by:
South African Medical Research Council
National Research Foundation (113416)
Text and Data Mining valid from 2019-01-29
Received: 20 April 2018
Accepted: 21 January 2019
First Online: 29 January 2019
Ethics approval and consent to participate
: Ethics approval for this study was obtained from the University of Cape Town Health Sciences Faculty Research Ethics committee (REC 257/2012) and all individuals (or their parents if < 18 years) signed informed consent to participate.
: Not applicable
: The authors declare that they have no competing interests.
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