1. Department of Internal Medicine, Faculty of Medicine and Pharmaceutical Science, Douala General Hospital, University of Douala, Douala, Cameroon
2. Faculty of Health Sciences, University of Buea, Buea, Cameroon
3. Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
4. Faculty of Medicine and Pharmaceutical Science, University of Douala, Douala, Cameroon
5. Department of Internal Medicine, Faculty of Medicine and Biomedical Sciences, Douala General Hospital Cameroon, University of Yaoundé I, Yaoundé, Cameroon
6. Faculty of Medicine and Biomedical Sciences, Yaounde General Hospital, University of Yaounde I, Yaoundé, Cameroon