Funding for this research was provided by:
Water Supply and Sanitation Collaborative Council (GSA/WSSCC/WP2/2019/06)
Received: 15 July 2020
Accepted: 13 December 2020
First Online: 2 January 2021
Ethics approval and consent to participate
: Ethics approval was not required for the conduct of this review.
: Not applicable.
: The authors declare they have no competing interests.