Ethical considerations
This study was conducted according to the Declaration of Helsinki, guidelines on Good Clinical Practice, and existing national legal and regulatory requirements. The study protocol was submitted and approved by the Madagascar Biomedical Research Ethics Committee (013/MSANP/CERBM) on February 26, 2018. All participants (parents/guardians and patients aged 7–14 years) received oral and written information concerning the study. Written informed consent was obtained from parents or guardians of all participants. If patients were unable to sign, a fingerprint was applied to the consent form. Children aged between 7 and 14 years old gave written assent to participate in the study. All signed informed consent forms will be kept for 15 years after the end of the study.