Received: 28 April 2021
Accepted: 14 June 2021
First Online: 2 August 2021
Ethics approval and consent to participate
: The study protocol was approved by the Medical Research Ethics Committee of Faculty of Medicine, Sohag University. An official permission was obtained from director of Health Insurance Institute for Upper Egypt for the studied children. Central Agency for Public Mobilization and Statistics (CAPMAS), Issue number 771 and Ministry of Education, Sohag Governorate, for collecting data for the control children. Informed consent was obtained from the caregivers of the children participating in the study. The researchers assured voluntary participation and confidentiality of each child who agrees to participate in this study.
: Consent for publication was obtained.
: All authors declare that they have no competing interests.