1. Department of Infectious Diseases, Inselspital, Bern University Hospital, University of Bern , Bern , Switzerland
2. Graduate School of Health Sciences, University of Bern , Bern , Switzerland
3. Division of Infectious Diseases and Hospital Epidemiology, Cantonal Hospital St Gallen , St Gallen , Switzerland
4. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich , Zurich , Switzerland
5. Institute of Medical Virology, University of Zurich , Zurich , Switzerland
6. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, University of Basel , Basel , Switzerland
7. Service of Infectious Diseases, University Hospital Lausanne, University of Lausanne , Lausanne , Switzerland
8. Division of Infectious Diseases, University Hospital Geneva, University of Geneva , Geneva , Switzerland
9. Division of Infectious Diseases, Ente Ospedaliero Cantonale, University of Southern Switzerland , Lugano , Switzerland
10. Positive Council , Zurich , Switzerland