1. General Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton SO16 6YD, UK
2. Department of Infection, Hampshire Hospitals NHS Foundation Trust, Royal Hampshire County Hospital, Romsey Road, Winchester SO22 5DG, UK
3. NIHR Southampton Clinical Research Facility and NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, and the University of Southampton, Tremona Road, Southampton SO16 6YD, UK
4. Faculty of Medicine, University of Southampton, Tremona Road, Southampton SO16 6YD, UK
5. Department of Infection, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton SO16 6YD, UK