1. Imperial College London, London, United Kingdom
2. Infection Control Programme and WHO Collaborating Centre on Patient Safety, University of Geneva Hospitals, Geneva, Switzerland
3. Swiss Federal Office of Public Health, Bern, Switzerland
4. Infection Control Programme, Cantonal Hospital Authority, Ticino, Switzerland
5. Institute of Hygiene and Environmental Medicine, Charité University Medicine Berlin, Berlin, Germany
6. Department of Infectious Diseases, Central Institute, Valais Hospital, Sion, Switzerland
7. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland