1. Department of Infectious Diseases, Bern University Hospital and University of Bern
2. Institute of Social and Preventive Medicine, University of Bern
3. Regional Hospital, Lugano
4. University Hospital Lausanne
5. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich
6. Cantonal Hospital, St. Gallen
7. University Hospital Basel
8. University Hospital Geneva, Switzerland