Affiliation: | 1. Department of Infectious Diseases, Bern University Hospital, University of Bern, Bern, Switzerland;2. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland;3. Institute of Medical Virology, University of Zurich, Zurich, Switzerland;4. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, University of Basel, Basel, Switzerland;5. Division of Infectious Diseases, University Hospital Lausanne, Lausanne, Switzerland;6. Division of Infectious Diseases and Hospital Epidemiology, Cantonal Hospital St Gallen, St Gallen, Switzerland;7. Institute for Infectious Diseases, University of Bern, Bern, Switzerland;8. Division of Infectious Diseases, Regional Hospital Lugano, Lugano, Switzerland |