Received: 22 March 2018
Accepted: 21 June 2018
First Online: 19 July 2018
Ethics approval and consent to participate
: Ethics approval was granted from Stellenbosch University’s Health Research Ethics Committee (S15/07/161) and permission was also given by the Western Cape Department of Health. All participants gave written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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