Received: 5 October 2017
Accepted: 5 December 2018
First Online: 19 December 2018
Ethics approval and consent to participate
: Prior to participation in this study, parents or guardians of children signed a written informed consent.The Ethic Committee of Biomedical Research, Medical School and Pharmacy, University Mohammed V<sup>th</sup>, Rabat, gave the approval for this study. Committees’ reference: 1222/2010.
: Not applicable.
: The authors declare that they have no competing interests.
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