Received: 8 January 2020
Accepted: 14 February 2020
First Online: 31 March 2020
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Faculty of Medicine, Fayoum University. Child assents and parents’ consent were obtained from both the participants and their parents. The number of approval is not applicable.
: Not applicable.
: The authors declare that they have no competing interests.