Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland.|Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zürich, University of Zürich, Zürich, Switzerland.|Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zürich, University of Zürich, Zürich, Switzerland.|Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland.