Risk Factors for Community-Onset Bloodstream Infection With Extended-Spectrum β-lactamase-producing Enterobacteriaceae: National Population-Based Case-Control Study

Clin Microbiol Infect. 2019 Nov;25(11):1408-1414. doi: 10.1016/j.cmi.2019.04.002. Epub 2019 Apr 13.


Objectives: The aim was to investigate risk factors for community-onset bloodstream infections with extended-spectrum β-lactamase-producing Enterobacteriaceae (EPE BSI).

Methods: It is mandatory to report EPE BSI to a national register at the Public Health Agency of Sweden. Using this register, we performed a population-based case-control study from 2007 to 2012 of 945 cases and 9390 controls. Exposure data on comorbidity, hospitalization, in- and outpatient antibiotic consumption and socio-economic status were collected from hospital and health registers.

Results: The overall incidence of EPE BSI was 1.7 per 100 000 person-years. The 30-day mortality was 11.3%. Urological disorders inferred the highest EPE BSI risk, adjusted odds ratio (aOR) 4.32 (95% Confidence Interval (CI) 3.41-5.47), followed by immunological disorders, aOR 3.54 (CI 2.01-6.23), haematological malignancy, aOR 2.77 (CI 1.57-4.87), solid tumours, aOR 2.28 (1.76-2.94) and diabetes, aOR 2.03 (1.58-2.61). Consumption of fluoroquinolones or mostly non-EPE-active antibiotics with selective Gram-negative spectrum of activity within the previous 3 months was associated with EPE BSI, aORs 5.52 (CI 2.8-11.0) and 3.8, CI 1.9-7.7) respectively. There was a dose-response relationship in EPE BSI risk with increasing number of consecutive regimens. Antibiotic consumption >3 months before EPE BSI was not associated with increased risk. Higher age, malignancies and education ≤12 years (aORs >2) were associated with increased 30-day mortality.

Conclusions: Targeted interventions should be directed towards improving care for patients with immunosuppression, urological disorders and subjects with lower socio-economic status. Antibiotic stewardship should focus on reduction of fluoroquinolones.

Keywords: Antibiotic consumption; Antibiotic resistance; Bloodstream infection; Case–control study; Cephalosporins; ESBL; Epidemiology; Escherichia coli; Fluoroquinolones; Risk factors.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / therapeutic use
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Community-Acquired Infections / epidemiology*
  • Community-Acquired Infections / microbiology
  • Drug Utilization / statistics & numerical data
  • Enterobacteriaceae / enzymology*
  • Enterobacteriaceae / isolation & purification
  • Enterobacteriaceae Infections / epidemiology*
  • Female
  • Hospitalization / statistics & numerical data
  • Humans
  • Incidence
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Risk Factors
  • Sepsis / epidemiology*
  • Sepsis / microbiology
  • Socioeconomic Factors
  • Sweden / epidemiology
  • Young Adult
  • beta-Lactamases / metabolism*


  • Anti-Bacterial Agents
  • beta-Lactamases