Received: 14 March 2021
Accepted: 19 October 2021
First Online: 27 October 2021
: The study protocol was approved by the Research and Ethics Committee of the Faculty of Medicine and Health Sciences, University of Science and Technology, Sana’a, Yemen (Approval No. EAU/UST122). Written informed consent was obtained from guardian of all children after explaining the study objectives.
: Not applicable.
: The authors declare no competing interests.