title: Risks factors for infections with extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae at a tertiary care university hospital in Switzerland.
abstract: BACKGROUND
  There are considerable geographical differences in the occurrence of extended-spectrum beta-lactamase(ESBL)-producing bacteria, both in the community and in the hospital setting. Our aim was to assess risk factors for blood stream, urinary tract, and vascular catheter-associated infections with ESBL-producing Escherichia coli and Klebsiella pneumoniae at a tertiary care hospital in a low-prevalence country.
  
  
  METHODS
  We performed a case-control study comparing 58 patients with infections due to ESBL-producing E. coli orK. pneumoniae vs 116 controls with infections due to non-ESBL producing organisms at the University Hospital Zurich, Switzerland, between 1 July 2005 and 30 June 2007.
  
  
  RESULTS
  Cases included 15 outpatients and 43 inpatients. Multivariable analyses found three risk factors for ESBL-producing isolates: begin of symptoms or recent antibiotic pre-treatment in a foreign country (odds ratio [OR] 27.01,95% confidence interval [CI] 2.38-1,733.28], p = 0.042),antibiotic therapy within the year preceding the isolation of the ESBL-producing strain (OR 2.88, 95% CI 1.13-8.49,p = 0.025), and mechanical ventilation (OR 10.56, 95% CI 1.06-579.10, p = 0.042).
  
  
  CONCLUSIONS
  The major risk factors for infections due to ESBL-producing bacteria were travel in high-prevalence countries, prior antibiotic use, and mechanical ventilation during a stay in the intensive care unit. Community-acquired infections were documented in 17% of the patients.An early identification of risk factors is crucial to providing the patients an optimal empiric antibiotic therapy and to keep the use of carbapenems to a minimum.
authors.affiliation: University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: S P
authors.initials: SP
authors.lastname: Kuster
authors.forename: B
authors.initials: B
authors.lastname: Hasse
authors.forename: V
authors.initials: V
authors.lastname: Huebner
authors.forename: V
authors.initials: V
authors.lastname: Bansal
authors.forename: R
authors.initials: R
authors.lastname: Zbinden
authors.forename: C
authors.initials: C
authors.lastname: Ruef
authors.forename: B
authors.initials: B
authors.lastname: Ledergerber
authors.forename: R
authors.initials: R
authors.lastname: Weber
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D004926:Escherichia coli / Q000201:enzymology* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D006785:Hospitals, University; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000302:isolation & purification; D012307:Risk Factors; D013557:Switzerland / Q000453:epidemiology; D014195:Travel; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases