Funding for this research was provided by:
Indonesia Endowment Fund for Education (20151022084537)
Received: 6 August 2019
Accepted: 9 December 2019
First Online: 28 January 2020
Ethics approval and consent to participate
: This study was approved by the Medical Health Research Ethics Committee, Universitas Gadjah Mada, Indonesia (KE/FK/0290/EC/2017), and the Research Ethics Committee of the London School of Hygiene and Tropical Medicine (11944). Written individual informed consent was obtained from all participants in this study.
: Not applicable.
: The authors declare that they have no competing interests.