1. Reference Microbiology, National Infection Service, Public Health England, 61 Colindale Avenue, London, UK
2. Healthcare-Associated Infection & Antimicrobial Resistance Division, National Infection Service, Public Health England, 61 Colindale Avenue, London, UK
3. Statistics, Modelling and Economics Department, National Infection Service, Public Health England, 61 Colindale Avenue, London, UK