Received: 11 March 2020
Accepted: 7 July 2020
First Online: 21 September 2020
Ethics approval and consent to participate
: Parents of the children have given their written informed consent to participate in the study. The study protocol has been approved by the IRB committee of Mansoura Faculty of Medicine, Mansoura University, Egypt (M.S./119).
: Not applicable.
: The authors declare that they have no competing interests.