Received: 12 February 2019
Accepted: 26 September 2019
First Online: 7 October 2019
Ethics approval and consent to participate
: A written consent from participants or guardians, and assent in cases where participants were children were obtained. Ethical approval for the study was granted by the Ethics Review Board, University of Nigeria Teaching Hospital, Enugu, South Eastern Nigeria (Approval number: NHREC/05/01/2008B-FWA00002458-IRB00002323).
: Not applicable.
: The authors declare that they have no competing interests.