1. Faculty of Health Sciences, University of Buea, PO Box 63, Buea, Cameroon
2. Internal Medicine Unit, Buea Regional Hospital, PO Box 32, Buea, Cameroon
3. Department of Internal Medicine and Specialties, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, PO Box 1364, Yaoundé, Cameroon
4. Department of Medicine, Groote Schuur Hospital and University of Cape Town, 7925 Cape Town, South Africa
5. Medical Diagnostic Center, PO Box 6230, Yaoundé, Cameroon
6. Harvard TH Chan School of Public Health, Harvard University, Boston, MA, USA
7. Department of Public Health, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, PO Box 1364, Yaoundé, Cameroon
8. Department of Epidemiology and Public Health, Pasteur Center of Cameroon, PO Box 1274, Yaoundé, Cameroon
9. Internal Medicine Unit, Yaoundé University Hospital Centre, PO Box 4806, Yaoundé, Cameroon