1. Nuffield Department of Primary Care Health Sciences, University of Oxford , Oxford , UK
2. National Institute for Health and Care Research (NIHR) Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, University of Oxford , Oxford , UK
3. Clinical and Public Health, UK Health Security Agency , London , UK
4. Nuffield Department of Population Health, University of Oxford , Oxford , UK
5. Nuffield Department of Medicine, University of Oxford , Oxford , UK
6. NIHR Biomedical Research Centre , Oxford , UK