1. Department of General, Visceral and Transplantation Surgery and Study Center of the German Surgical Society; University Hospital Heidelberg; Heidelberg Germany
2. Institute of Hygiene and Environmental Medicine, University Medicine Greifswald; Greifswald Germany
3. Hygiene-North GmbH; Greifswald Germany
4. Department of Infection Control and Hospital Epidemiology; Medical University of Vienna, Vienna General Hospital; Vienna Austria
5. Department of Dermatology, Venereology and Allergology; University Hospital Essen; Essen Germany