Received: 5 June 2017
Accepted: 4 February 2018
First Online: 20 February 2018
Ethics approval and consent to participate
: The informed consent of the parents and children were obtained prior to the blood testing. Any parent or child who did not wish to be blood tested was allowed to withdraw from the survey. Furthermore, a ‘collective consent’ was obtained from the communities of the villages.
: Not applicable.
: The authors declare that they have no competing interests.