1. Internal Medicine Unit, Douala General Hospital, Cameroon
2. Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Cameroon
3. Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Cameroon
4. Faculty of Health Sciences, University of Buea, Cameroon
5. London School of Hygiene and Tropical Medicine, University of London, UK
6. Division of Gastroenterology and Hepatology, Department of Medicine, Medical College of Wisconsin, USA