Funding for this research was provided by:
Wellcome Trust (203077_Z_16_Z)
Received: 17 March 2019
Accepted: 4 June 2019
First Online: 8 July 2019
Ethics approval and consent to participate
: Ethical approval was granted by KEMRI SSC/ERC committees prior to 2010, then subsequently by KEMRI SERU. Written informed consent was taken from guardians with verbal explanations and forms in local languages.
: The authors declare that they have no competing interests.