Received: 13 March 2020
Accepted: 2 September 2020
First Online: 21 September 2020
Ethics approval and consent to participate
: This study was approved by the National Ethics Committee for Health Research in Lao PDR (reference No. 083/NECHR) and by the Ethics Committee Northwest and Central Switzerland (reference No. 2018–00594).
: Not applicable.
: The authors declare that they have no competing interests.