1. Department of Internal Medicine, Division of Infectious Diseases, Thurgau Hospital Group, Switzerland
2. Department of Infectious Diseases, Bern University Hospital, University of Bern, Switzerland
3. Infection Control Programme, University of Geneva Hospitals and Faculty of Medicine, Geneva, Switzerland
4. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Switzerland
5. Service of Hospital Preventive Medicine, Lausanne University Hospital, Switzerland
6. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, University of Basel, Switzerland