Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon;
Laquintinie Hospital of Douala, Douala, Cameroon;
Faculty of Medicine and Biomedical Sciences, University of Yaounde I, Yaounde, Cameroon;
Faculty of Health Sciences, University of Buea, Buea, Cameroon;
Douala General Hospital, Douala, Cameroon;