Outbreak of vancomycin-resistant Enterococcus spp. in an Italian general intensive care unit

• DOI: 10.1111/j.1469-0691.2005.01331.x
• Publication Date: 2006-01-18T14:21:37Z
• Authors: M. Peta; E. Carretto; D. Barbarini; A. Zamperoni; L. Carnevale; L. Perversi; M. Pagani; M.G. Bonora; R. Fontana; P. Marone; M. Langer
• Keywords: Microbiology (medical); Adult; DNA, Bacterial; Male; 0301 basic medicine; Genotype; Epidemiology; Intensive Care Unit; Epidemiology; Intensive care unit; Outbreak; Ribotyping; Surveillance; Vancomycin-resistant enterococci; intensive care unit; Ribotyping; Disease Outbreaks; 03 medical and health sciences; Cluster Analysis; Humans; ribotyping; Gram-Positive Bacterial Infections; Aged; Cross Infection; Infection Control; outbreak; Outbreak; Vancomycin Resistance; General Medicine; Sequence Analysis, DNA; Length of Stay; Middle Aged; vancomycin-resistant enterococci; 3. Good health; Intensive Care Units; Infectious Diseases; Italy; Vancomycin-resistant enterococci; surveillance; Female; Enterococcus

Following the identification of two clinical isolates of vancomycin-resistant enterococci (VRE) from intensive care unit (ICU) patients, a surveillance programme detected that six of eight ICU patients were colonised by VRE. Standard epidemic control measures were instituted in the ICU. During a 16-month period, 13 (2.5%) of 509 ICU patients had VRE-positive swabs upon admission, and 43 (8.7%) of 496 VRE-negative patients were colonised by VRE in the ICU. Patients who acquired VRE in the ICU had a longer ICU stay (p < 0.0001). No other statistically significant differences were demonstrated. Two patients had documented infection (infection/colonisation index, 3.6%; overall VRE infection frequency, 0.4%), but both recovered and were discharged. VRE colonisation did not increase the mortality rate. Automated ribotyping identified three clusters containing, respectively, the first 52 Enterococcus faecium isolates, two Enterococcus faecalis isolates, and two further isolates of E. faecium. Multilocus sequence typing demonstrated that two E. faecium isolates representative of the two ribotypes belonged to sequence types 78 and 18, and that these two isolates belonged to the epidemic lineage C1, which includes isolates with a wide circulation in northern Italy. The outbreak was controlled by continuous implementation of the infection control programme, and by the opening of a new unit with an improved structural design and hand-washing facilities.