title: Epidemiology and risk factors for extended-spectrum beta-lactamase-producing organisms: a case control study at a tertiary care center in Lebanon.
abstract: BACKGROUND
  Infections caused by extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacilli constitute a growing problem worldwide. At the American University of Beirut Medical Center (AUBMC), we have observed a significant rise in the rates of ESBL-producing organisms over the past 5 years.
  
  
  METHODS
  Using a case control study design, we compared 99 patients with infections caused by ESBL-producing Escherichia coli and Klebsiella species and 99 frequency-matched controls from which ESBL-nonproducing isolates were recovered at AUBMC.
  
  
  RESULTS
  The most notable risk factor for acquiring infections with ESBL-producing organisms was antibiotic consumption within 30 days of the infection (OR, 7.06; 95% CI: 3.27-15.24), with third-generation cephalosporins being associated with the highest risk (OR, 28.4; 95% CI: 3.7-215.8). Other risk factors included recent surgery, presence of a urinary catheter, and need for mechanical ventilation. Moreover, cases had a longer mean duration of hospitalization and were more likely to have relapse of their infection than controls.
  
  
  CONCLUSIONS
  Recent antibiotic use is by far the most important predisposing factor to infection with ESBL-producing organisms. Such infections are associated with prolonged hospital stay and increased morbidity. Attention should be redirected toward the unjustified liberal use of broad-spectrum antibiotics both in the hospital and in the community.
authors.affiliation: Division of Infectious Diseases, American University of Beirut, Lebanon.
authors.forename: Zeina A
authors.initials: ZA
authors.lastname: Kanafani
authors.forename: Abla
authors.initials: A
authors.lastname: Mehio-Sibai
authors.forename: George F
authors.initials: GF
authors.lastname: Araj
authors.forename: Mona
authors.initials: M
authors.lastname: Kanaan
authors.forename: Souha S
authors.initials: SS
authors.lastname: Kanj
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D016022:Case-Control Studies; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D005260:Female; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology; D007861:Lebanon / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases