Affiliation: | 1. Norwich Medical School, University of East Anglia, Norwich, UK;2. Department of Epidemiology and Population Health, Institute of Infection and Global Health, Leahurst Campus, University of Liverpool, Liverpool, UK;3. School of Environmental Sciences, University of East Anglia, Norwich, UK;4. Norwich Medical School, University of East Anglia, Norwich, UK NIHR Health Protection Research Unit in Gastrointestinal Infections, Liverpool, UK;5. NIHR Health Protection Research Unit in Gastrointestinal Infections, Liverpool, UK School of Environmental Sciences, University of East Anglia, Norwich, UK;6. NIHR Health Protection Research Unit in Gastrointestinal Infections, Liverpool, UK Institute of Population Health Sciences, University of Liverpool, Liverpool, UK |