Funding for this research was provided by:
Children's Investment Fund Foundation (10154059)
Received: 4 October 2018
Accepted: 23 September 2019
First Online: 21 October 2019
Ethics approval and consent to participate
: Ethical approval was granted by the scientific and ethical review office of (Ref number: 047-01-2017; Version 001) and the LSHTM ethics committee (Ref number: 12268). Further administrative permissions were obtained from local government bureaus. The study objectives and procedures were explained, and an information sheet was provided prior to requesting consent. Written informed consent was obtained from each participant including agreement to be recorded using a digital audio recorder.
: All authors reviewed this manuscript and provided consent for publication.
: The authors declare that they have no competing interests.