1. Health Protection Agency, London Region Epidemiology Unit, London, United Kingdom
2. European Programme for Intervention Epidemiology Training, European Centre for Disease Prevention and Control, Stockholm
3. Health Protection Agency, North East and North Central London Health Protection Unit, London, United Kingdom
4. Homerton University Hospital NHS Foundation Trust, London, United Kingdom
5. Health Protection Agency, Novel and Dangerous Pathogens (NaDP) Laboratory, Centre for Emergency Preparedness and Response (CEPR), Porton Down, United Kingdom
6. Health Protection Agency, Gastrointestinal, Emerging and Zoonotic Infections (GEZI) Department, Centre for Infections, Colindale, United Kingdom