1. Department of Medicine, Lagos State University College of Medicine/Lagos State University Teaching Hospital, Lagos, Nigeria
2. GastroDerm Clinic, Lekki, Nigeria
3. Department of Medicine, Federal Medical Centre, Keffi, Nassarawa, Nigeria
4. Department of Medicine, University of Abuja Teaching Hospital, Abuja, Nigeria
5. Department of Medicine, Kaduna State University Teaching Hospital, Kaduna, Nigeria
6. Department of Medicine, University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria
7. Department of Medicine, University of Calabar Teaching Hospital, Calabar, Nigeria