University of Yaounde I - Yaounde Central Hospital, University of Douala - Department of Surgery, University of Yaounde I - Department of Internal Medicine and Specialities, University of Dschang - Faculty of Medicine and Pharmaceutical Sciences, University of Douala - Department of Medicine, University of Yaounde I - Department of Surgery and Specialities, University of Yaounde I - Yaounde Central Hospital, University of Yaounde I - Yaounde Central Hospital, University of Yaounde I - Department of Surgery and Specialities, University of Yaounde I - Department of Internal Medicine and Specialities, ANRS Cameroon, University of Yaounde I - Yaounde Central Hospital, University of Dschang - Faculty of Medicine and Pharmaceutical Sciences, University of Yaounde I - Yaounde Central Hospital, University of Yaounde I - Yaounde Central Hospital, University of Yaounde I - Department of Internal Medicine and Specialities, University of Yaounde I - Research - Health and Development, University of Yaounde I - Yaounde Central Hospital, University of Yaounde I - Department of Internal Medicine and Specialities, Ministry of Public Health Cameroon - Regional Public Health Delegation for the Centre, University of Yaounde I - Yaounde Central Hospital, Université Catholique de Louvain - Department of Infectious Diseases, Ministry of Public Health, University of Yaounde I - Department of Internal Medicine and Specialities, University of Yaounde I - Department of Surgery and Specialities, University of Yaounde I - Yaounde Central Hospital, Ministry of Public Health - Division of Health Operations Research, University of Yaounde I - Yaounde Central Hospital and University of Yaounde I - Department of Internal Medicine and Specialities