The incidence of urinary tract infection (UTI) due to extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has increased over recent years. Initial empirical therapy is often ineffective for these resistant isolates resulting in prolonged hospitalization and increased mortality. This study was conducted to determine the risk factors of UTI caused by ESBL E. coli in the emergency department (ED).

This is a retrospective case-control study at a university hospital in Korea with UTI patients who visited ED between June 2015 and December 2016. We compared case patients with ESBL E. coli UTI (n = 50) to control patients with non-ESBL-producing E. coli UTI (n = 100), which were matched for age and sex. Multivariate logistic regression analysis was used to explore risk factors.

Our study showed that hospital-acquired infection (OR = 3.86; 95% CI = 1.26–11.8; p = .017), prior UTI within 1 year (OR = 3.26; 95% CI = 1.32–8.05; p = .010), and underlying cerebrovascular disease (OR = 3.24; 95% CI = 1.45–7.25; p = .004) were independent risk factors for acquisition of ESBL-producing E. coli. Notably, 35 (70%) out of 50 case patients had community-acquired infection, and 68% and 54% of ESBL E. coli were resistance to ciprofloxacin and trimethoprim-sulfamethoxazole, respectively. On the contrary, 98% of ESBL E. coli was susceptible to amikacin.

The main risk factors identified in our study should be considered when treating UTI patients in ED. Amikacin may improve the outcome of empirical treatment without increasing carbapenem utilization.