From the *Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
†School of Health and Related Research, The University of Sheffield, Sheffield, United Kingdom.
The authors declare no conflict of interest.
Correspondence: Jan René Nkeck, MD, MSc, Postal Box 8009, Yaoundé, Cameroon. E-mail: firstname.lastname@example.org.
Online date: December 12, 2017