Intrahospital spread of vancomycin-resistant Enterococcus faecium in Sweden

During a 17-week period vancomycin-resistant Enterococcus faecium (VRE) was found in clinical specimens from 4 in-patients. All bacterial isolates were phenotypically VanA, showing high-level resistance to vancomycin (MIC 256 micrograms/ml) and teicoplanin (MIC 24-256 micrograms/ml). The corresponding gene (vanA) was detected with PCR in strains from 3 of the patients. Three patients had been hospitalized at the renal unit at Orebro Medical Centre Hospital (OMCH). The fourth patient, diagnosed in another hospital, had received treatment in the oncology unit at OMCH. All patients recovered without treatment specific for VRE. Isolates from 2 patients were indistinguishable by pulsed-field gel electrophoresis of genomic DNA. Genetically, these strains were related to the VRE isolates from the 2 other patients. Screening of hospital staff and other in-patients for gastrointestinal carriage of VRE was negative. Glycopeptide-resistant enterococci have not previously been found in OMCH. No new cases were identified during a 10-month follow-up period. Our cases represent the first nosocomial outbreak of VRE in Sweden.