Funding for this research was provided by:
United States Agency for International Development (AID-OAA-A-14-00057)
Received: 29 October 2020
Accepted: 12 December 2020
First Online: 7 January 2021
Ethics approval and consent to participate
: For each country ethical clearance was obtained from the Institutional Review Board of the Johns Hopkins University, Baltimore, USA and the respective national ethics committees or equivalent. All participants provided written informed consent prior to participation.
: Not applicable.
: The authors declare that they have no competing interests.