Received: 23 May 2019
Accepted: 28 October 2019
First Online: 2 December 2019
Ethics approval and consent to participate
: We received ethical clearance for this study from the Comité National d’Ethique de la Santé (CNES) of the Ministry of Health of the Democratic Republic of Congo in April 2015. Written consent was obtained from all respondents.
: Not applicable (no individual information reported).
: The authors declare that they have no competing interests.