1 Division of Digestive Diseases, St Mary's Hospital, Imperial College, London W2 1NY, UK; Department of Infectious Disease Epidemiology, School of Public Health, Imperial College, London, UK. Electronic address: [email protected].
2 Health Economics Group, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College, London, UK.
3 Health Economics Group, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College, London, UK; ISGlobal, Barcelona Centre for International Health Research, Hospital Clinic, Universitat de Barcelona, Barcelona, Spain.
4 Medical Research Council Laboratories, The Gambia Unit, Fajara, The Gambia; Unité d'Épidémiologie des Maladies Émergentes, Institut Pasteur, Paris, France.
5 Division of Digestive Diseases, St Mary's Hospital, Imperial College, London W2 1NY, UK; Medical Research Council Laboratories, The Gambia Unit, Fajara, The Gambia.
6 Department of Infectious Disease Epidemiology, School of Public Health, Imperial College, London, UK.
7 Division of Digestive Diseases, St Mary's Hospital, Imperial College, London W2 1NY, UK.