1 College of Medicine, Queen Elizabeth Central Hospital, Box 360, Blantyre, Malawi; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi; Department of Gastroenterology, University of Liverpool, Liverpool, UK.
2 College of Medicine, Queen Elizabeth Central Hospital, Box 360, Blantyre, Malawi. Electronic address: emmolyneux@gmail.com.