Funding for this research was provided by:
Bill and Melinda Gates Foundation (OPP1161450)
Received: 28 January 2020
Accepted: 8 June 2020
First Online: 15 June 2020
Ethics approval and consent to participate
: Since this study was considered as non-human subject research, it was exempt to require ethical approval and consent to participants.
: Not applicable.
: The authors declare that they have no competing interests.