Efficacy of admission screening for extended-spectrum beta-lactamase producing Enterobacteriaceae

PLoS One. 2013 Apr 26;8(4):e62678. doi: 10.1371/journal.pone.0062678. Print 2013.


Objective: We hypothesized that admission screening for extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) reduces the incidence of hospital-acquired ESBL-E clinical isolates.

Design: Retrospective cohort study.

Setting: 12 hospitals (6 screening and 6 non-screening) in Toronto, Canada.

Patients: All adult inpatients with an ESBL-E positive culture collected from 2005-2009.

Methods: Cases were defined as hospital-onset (HO) or community-onset (CO) if cultures were positive after or before 72 hours. Efficacy of screening in reducing HO-ESBL-E incidence was assessed with a negative binomial model adjusting for study year and CO-ESBL-E incidence. The accuracy of the HO-ESBL-E definition was assessed by re-classifying HO-ESBL-E cases as confirmed nosocomial (negative admission screen), probable nosocomial (no admission screen) or not nosocomial (positive admission screen) using data from the screening hospitals.

Results: There were 2,088 ESBL-E positive patients and incidence of ESBL-E rose from 0.11 to 0.42 per 1,000 inpatient days between 2005 and 2009. CO-ESBL-E incidence was similar at screening and non-screening hospitals but screening hospitals had a lower incidence of HO-ESBL-E in all years. In the negative binomial model, screening was associated with a 49.1% reduction in HO-ESBL-E (p<0.001). A similar reduction was seen in the incidence of HO-ESBL-E bacteremia. When HO-ESBL-E cases were re-classified based on their admission screen result, 46.5% were positive on admission, 32.5% were confirmed as nosocomial and 21.0% were probable nosocomial cases.

Conclusions: Admission screening for ESBL-E is associated with a reduced incidence of HO-ESBL-E. Controlled, prospective studies of admission screening for ESBL-E should be a priority.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Canada / epidemiology
  • Community-Acquired Infections / epidemiology
  • Community-Acquired Infections / microbiology
  • Cross Infection / epidemiology
  • Cross Infection / microbiology
  • Enterobacteriaceae / isolation & purification*
  • Enterobacteriaceae Infections / epidemiology
  • Enterobacteriaceae Infections / microbiology
  • Hospitals / statistics & numerical data*
  • Humans
  • Incidence
  • Mass Screening*
  • Patient Admission / statistics & numerical data*
  • Rectum / microbiology
  • beta-Lactamases / biosynthesis*


  • beta-Lactamases

Grant support

This work was supported by the Physician’s Services Incorporated Foundation (http://www.psifoundation.org/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.