Received: 18 February 2020
Accepted: 2 April 2020
First Online: 1 May 2020
Ethics approval and consent to participate
: Ethical approval for this study was received from the University of Cape Town Human Research Ethics Committee and Muhimbili University of Health and Allied Sciences Institutional Review Board. All participants provided written informed consent prior to participation.
: Not applicable.
: The authors declare that they have no competing interests.