1 Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany.
2 Institute of Virology, University Hospital Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany.
3 Department I of Internal Medicine, University Hospital Cologne, Faculty of Medicine, University of Cologne, German Center for Infection Research Partner Side Köln-Bonn, University of Cologne, Cologne, Germany.
4 Department of Hospital Hygiene and Infection Control, University Hospital Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany.