Clinical implications, risk factors and mortality following community-onset bacteremia caused by extended-spectrum β-lactamase (ESBL) and non-ESBL producing Escherichia coli

Abstract

Background/purpose: Infections caused by extended-spectrum β-lactamase (ESBL)-producing bacteria have become a serious clinical concern worldwide. The occurrence of ESBLs in Taiwan has been well-documented and is reviewed in recent publications. However, studies comparing community-onset bacteremia caused by ESBL- and non-ESBL-producing Escherichia coli are limited.

Methods: We retrospectively reviewed the medical records of patients with E. coli bacteremia who visited the emergency department of Kaohsiung Chang Gung Memorial Hospital from January 2005 to December 2006. Clinical data were collected to compare the clinical features of patients with ESBL-producing E. coli with those of patients with non-ESBL-producers and to identify the risk factors associated with ESBL-producing E. coli bacteremia.

Results: There were 404 episodes of community-onset E. coli bacteremia. The overall 30-day mortality rate was 11.4% (46/404) and the mortality rate of healthcare-associated infections was significantly higher than that of community-acquired infections [4/13 (30.8%) vs. 42/391 (10.7%); p= 0.049] Nonurinary focus was independently associated with an increased risk of fatality [47/178 (26.4%) vs. 4/226 (1.8%); p < 0.001]. The frequency of ESBL producers was 4.7% (19/404). Of these, four (21.1%) were associated with a long-term care facility. Significant risk factors associated with ESBL-producing E. coli bacteremia included recent antibiotic exposure (within 30 days) and urinary catheter placement. Although the trend was towards higher mortality in patients with ESBL-producing E. coli bacteremia, the difference did not reach statistical significance compared with the mortality of patients with non-ESBL E. coli bacteremia.

Conclusion: Fewer than 5% of community-onset E. coli bacteremia episodes in Southern Taiwan were due to ESBL-producers. Prior antibiotic use within 30 days and urinary catheter placement were independently associated with ESBL-producing E. coli bacteremia.