1. College of Medicine and Health, University of Exeter, Exeter, United Kingdom;
2. Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom;
3. Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, Imperial College, London, United Kingdom;
4. Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom;
5. Department of Food and Resource Economics, Faculty of Science, University of Copenhagen, Frederiksberg, United Kingdom