Received: 13 September 2018
Accepted: 4 June 2019
First Online: 25 June 2019
Ethics approval and consent to participate
: Ethical clearance was obtained from the University of Gondar, College of Medicine and Health Sciences, School of Biomedical and Laboratory Sciences Research and Ethical Review Committee. Permission was taken from Gondar town Health and Education Offices, and the school authorities. Students and their parents were notified and necessary explanations were also given about the purposes, procedure and ethical issues of the study. The written informed consent was obtained from the parents/guardians of study subjects for each study subject less than 18 years old and oral assent was also obtained from study subjects in the school from children who were greater than 7 years old.
: Not applicable.
: The authors declare that they have no competing interests.