Funding for this research was provided by:
University of Colombo (AP/3/2/2014/RG/13)
National Institutes of Health (U01AI136033)
Received: 6 February 2019
Accepted: 11 June 2019
First Online: 15 July 2019
Ethics approval and consent to participate
: The study received the approval from the Ethics Review Committee, Faculty of Medicine, University of Colombo. Informed written consent was obtained from all the individuals prior to recruitment.
: Not applicable.
: The authors declare that they have no competing interests.