1. University of Cape Town and Groote Schuur Hospital, Anzio Road, Observatory, Cape Town 7945, South Africa
2. Internal Medicine Unit, Faculty of Medicine and Health Sciences, University of Zimbabwe, Harare, Zimbabwe
3. School of Medicine and Clinical Sciences, Levy Mwanawasa Medical University, Lusaka, Zambia
4. Division of Gastrointestinal/Surgical Oncology, Department of Surgery, Obafemi Awolowo University/Teaching Hospitals Complex, Ile-Ife, Osun, Nigeria
5. Department of Pathology, College of Medicine and Allied Health Sciences/Teaching Hospitals Complex Highest University of Sierra Leone, Freetown, Sierra Leone
6. Department of Medicine, Faculty of Health Sciences, University of Cape Town, Rondebosch, Western Cape, South Africa
7. Barts and the London School of Medicine and Dentistry, Blizard Institute, Queen Mary University of London, London, UK