1. North East and North Central London Health Protection Unit, Health Protection Agency, London, United Kingdom
2. Homerton University Hospital, London, United Kingdom
3. Laboratory for Novel and Dangerous Pathogens, Health Protection Agency, London, United Kingdom
4. Centre for Infections, Health Protection Agency, London, United Kingdom
5. London Regional Director’s Office, Health Protection Agency, London, United Kingdom
6. Health Protection Agency, Central Office, London, United Kingdom