Received: 16 September 2016
Accepted: 9 January 2018
First Online: 16 January 2018
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of the Faculty of Health Sciences, University of Buea, Cameroon. Participants were not exposed to any risk by taking part in the study. Parents or guardians signed a written informed consent form, as approval for their children to be participants.
: Not applicable.
: The authors declare that they have no competing interests.
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