Funding for this research was provided by:
Department for International Development, UK Government (201446)
Received: 21 November 2018
Accepted: 31 May 2019
First Online: 10 June 2019
Ethics approval and consent to participate
: Ethical approval was obtained from the University of KwaZulu-Natal Biomedical Research Ethics Committee (BREC) (Ethical Clearance Number HSS/0880/011; BE258/14).
: Not applicable.
: The authors declare that they have no competing interests.