title: Changing epidemiology of infections due to extended spectrum beta-lactamase producing bacteria.
abstract: BACKGROUND
  Community-associated infections caused by extended-spectrum beta-lactamase (ESBL) producing bacteria are a growing concern.
  
  
  METHODS
  Retrospective cohort study of clinical infections due to ESBL-producing bacteria requiring admission from 2006-2011 at a tertiary care academic medical center in Providence, RI.
  
  
  RESULTS
  A total of 321 infections due to ESBL-producing bacteria occurred during the study period. Fifty-eight cases (18%) were community-acquired, 170 (53%) were healthcare-associated, and 93 (29%) were hospital-acquired. The incidence of ESBL infections per 10,000 discharges increased during the study period for both healthcare-associated infections, 1.9 per year (95% CI 1-2.8), and for community-acquired infections, 0.85 per year (95% CI 0.3-1.4) but the rate remained unchanged for hospital-acquired infections. For ESBL-producing E. coli isolates, resistance to both ciprofloxacin and trimethoprim-sulfamethoxazole was 95% and 65%, respectively but 94% of isolates were susceptible to nitrofurantoin.
  
  
  CONCLUSIONS
  Community-acquired and healthcare-associated infections due to ESBL-producing bacteria are increasing in our community, particularly urinary tract infections due to ESBL-producing E. coli. Most isolates are resistant to oral antibiotics commonly used to treat urinary tract infections. Thus, our findings have important implications for outpatient management of such infections.
authors.forename: Steven Z
authors.initials: SZ
authors.lastname: Kassakian
authors.affiliation: Department of Medicine, Warren Alpert Medical School of Brown University, Providence, RI, USA. lmermel@lifespan.org.
authors.forename: Leonard A
authors.initials: LA
authors.lastname: Mermel