1 Institute of Hygiene and Environmental Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany; National Reference Center for the Surveillance of Nosocomial Infections, Berlin 12203, Germany; LADR Medizinisches Versorgungszentrum Neuruppin, Neuruppin, Germany. Electronic address: tobias.kramer@charite.de.
2 Institute of Hygiene and Environmental Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany; National Reference Center for the Surveillance of Nosocomial Infections, Berlin 12203, Germany.