title: Vancomycin-resistant Enterococcus outbreak in a neonatal intensive care unit: epidemiology, molecular analysis and risk factors.
abstract: BACKGROUND
  Vancomycin-resistant Enterococcus faecium (VRE) may cause outbreaks in neonatal intensive care units (NICU). We describe a biphasic VRE outbreak and identify risk factors for VRE acquisition.
  
  
  METHODS
  After the occurrence of 2 cases of VRE infections in a 44-bed NICU, a bundle of interventions was implemented that included active surveillance cultures for VRE, enhanced infection control measures, and audits on antimicrobial use, from June to December 2008. Analysis was performed using polymerase chain reaction and pulse-field gel electrophoresis techniques. A case-control study was conducted to identify risk factors.
  
  
  RESULTS
  Among 253 neonates screened, 101 (39.9%) were found to be colonized with VRE. During the first 9 weeks of the study period, 59 new cases were detected. Molecular analysis showed 1 predominant clone. During weeks 10-12, no new cases of VRE colonization were detected; however, at week 13, just when the outbreak appeared to be over, a second wave occurred, with 42 new cases and multiple clones detected. Multivariate analysis identified administration of antimicrobial therapy for late-onset neonatal sepsis and hospitalization during the first month of this outbreak as significant risk factors for VRE colonization.
  
  
  CONCLUSIONS
  Both a high prevalence of VRE colonization and antimicrobial use promoted the transmission of VRE during this biphasic outbreak. Adherence to infection control measures and antimicrobial stewardship policies are of utmost importance.
authors.affiliation: Third Department of Pediatrics, Aristotle University School of Medicine, Hippokration General Hospital, Thessaloniki, Greece.
authors.forename: Elias
authors.initials: E
authors.lastname: Iosifidis
authors.forename: Ioanna
authors.initials: I
authors.lastname: Evdoridou
authors.forename: Eleni
authors.initials: E
authors.lastname: Agakidou
authors.forename: Elpis
authors.initials: E
authors.lastname: Chochliourou
authors.forename: Efthimia
authors.initials: E
authors.lastname: Protonotariou
authors.forename: Konstantina
authors.initials: K
authors.lastname: Karakoula
authors.forename: Ioannis
authors.initials: I
authors.lastname: Stathis
authors.forename: Danai
authors.initials: D
authors.lastname: Sofianou
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Drossou-Agakidou
authors.forename: Spyros
authors.initials: S
authors.lastname: Pournaras
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Roilides
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks; D004363:Drug Utilization / Q000706:statistics & numerical data; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000145:classification* / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D007231:Infant, Newborn; D015931:Intensive Care, Neonatal; D008297:Male; D017720:Molecular Epidemiology; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial
keywords: Colonization; Glycopeptides; Gram positive cocci; Infection control; Multidrug resistance; Neonates