title: Prolonged outbreak of Serratia marcescens in Tartu University Hospital: a case-control study.
abstract: BACKGROUND
  The aim of our study was to investigate and control an outbreak and identify risk factors for colonization and infection with Serratia marcescens in two departments in Tartu University Hospital.
  
  
  METHODS
  The retrospective case-control study was conducted from July 2005 to December 2006. Molecular typing by pulsed field gel electrophoresis was used to confirm the relatedness of Serratia marcescens strains. Samples from the environment and from the hands of personnel were cultured.
  
  
  RESULTS
  The outbreak involved 210 patients, 61 (29%) developed an infection, among them 16 were invasive infections. Multivariate analysis identified gestational age, arterial catheter use and antibiotic treatment as independent risk factors for colonization and infection with Serratia marcescens. Molecular typing was performed on 83 Serratia marcescens strains, 81 of them were identical and 2 strains were different.
  
  
  CONCLUSIONS
  Given the occasionally severe consequences of Serratia marcescens in infants, early implementation of aggressive infection control measures involving patients and mothers as well as the personnel is of utmost importance.
authors.affiliation: Department of Infection Control, Tartu University Hospital, Puusepa 1a, 50406, Tartu, Estonia. vivika.adamson@kliinikum.ee
authors.forename: Vivika
authors.initials: V
authors.lastname: Adamson
authors.forename: Piret
authors.initials: P
authors.lastname: Mitt
authors.forename: Heti
authors.initials: H
authors.lastname: Pisarev
authors.forename: Tuuli
authors.initials: T
authors.lastname: Metsvaht
authors.forename: Kaidi
authors.initials: K
authors.lastname: Telling
authors.forename: Paul
authors.initials: P
authors.lastname: Naaber
authors.forename: Matti
authors.initials: M
authors.lastname: Maimets
mesh_terms: D016022:Case-Control Studies; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D004783:Environmental Microbiology; D004957:Estonia / Q000453:epidemiology; D005260:Female; D006225:Hand / Q000382:microbiology; D006785:Hospitals, University; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D058889:Molecular Typing; D012307:Risk Factors; D016868:Serratia Infections / Q000453:epidemiology* / Q000382:microbiology; D012706:Serratia marcescens / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*