1. Department of Medicine and Specialties; Faculty of Medicine and Biomedical Sciences; The University of Yaoundé 1; Yaoundé Cameroon
2. Department of Internal Medicine; The Yaoundé University Teaching Hospital; Yaoundé Cameroon
3. South African Medical Research Council; University of Cape Town; Cape Town South Africa
4. Higher Institute of Health Sciences; Bangangté Cameroon
5. Department of Clinical Sciences; Faculty of Medicine and Pharmaceutical Sciences; The University of Douala; Douala Cameroon
6. Department of Internal Medicine; Yaoundé Central Hospital; Yaoundé Cameroon