Funding for this research was provided by:
Wellcome Trust (106919/Z/15/Z)
Text and Data Mining valid from 2019-01-03
Received: 20 July 2018
Accepted: 12 December 2018
First Online: 3 January 2019
Compliance with ethical standards
: The study has been approved by the ethics board of LSHTM/Sangath. All participants had given their informed consent prior to their inclusion in the study.
: The content of this publication is solely the responsibility of the authors. On behalf of all authors, the corresponding author states that there is no conflict of interest.