Funding for this research was provided by:
United States Agency for International Development (72067419CA00004, AID-674-A-12-00029)
Received: 5 September 2019
Accepted: 18 November 2019
First Online: 5 December 2019
Ethics approval and consent to participate
: Ethical approval was provided by the Human Research Ethics Committee (Medical) of the University of the Witwatersrand (M160506). The study protocol was reviewed by the Institutional Review Board of the University of Witwatersrand who approved the data collection without informed consent.
: Not applicable.
: The authors declare that they have no competing interests.