1 Institute for Medical Microbiology, Virology and Hygiene, Department for Infection Prevention and Control, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
2 HyKoMed GmbH, Dortmund, Germany.
3 German Society of Hospital Hygiene, Berlin, Germany.
4 University Medicine Greifswald, Greifswald, Germany. Electronic address: guenter.kampf@uni-greifswald.de.