Urosepsis due to extended-spectrum ß-lactamase–Producing Escherichia coli: A retrospective, single-centre review of risk factors and clinical outcomes

Abstract

Background: Extended-spectrum ß-lactamase (ESBL)–producing Enterobacteriaceae are pathogens that are implicated in urosepsis and may be associated with greater morbidity and mortality than non-ESBL Enterobacteriaceae. Identification of risk factors for ESBL infection may facilitate the selection of appropriate empiric therapy. Objectives: The primary objectives were to determine the cumulative incidence of ESBL urosepsis, to identify major risk factors for ESBL urosepsis, and to determine the impact of international travel on development of ESBL urosepsis in an ethnically diverse Canadian population. The secondary objective was to characterize the outcomes of patients with ESBL urosepsis. Methods: A single-centre retrospective nested case–control study was conducted from January 2011 to June 2013. The study cohort consisted of adult patients with urosepsis and positive results on blood culture for ESBL-producing and non–ESBL-producing Enterobacteriaceae. Multivariate analysis was then used to determine risk factors for ESBL urosepsis. Results: The cumulative incidence of ESBL urosepsis at the study site was 19.4% (58/299) over 2.5 years. The 58 cases of ESBL urosepsis were compared with 118 controls (patients with urosepsis caused by non-ESBL Enterobacteriaceae). Significant predictors of ESBL urosepsis were chronic renal insufficiency (odds ratio [OR] 4.66, 95% confidence interval [CI] 1.96–11.08; p < 0.001) and travel to an endemic region in the previous 6 months (OR 4.62, 95% CI 1.17–18.19; p = 0.029), as well as Punjabi or Hindi as the primary language (OR 3.25, 95% CI 1.45–7.29; p = 0.004) and male sex (OR 2.65, 95% CI 1.21–5.80; p = 0.015). Patients with ESBL urosepsis had worse prognosis—in terms of death or discharge with palliative measures only—than those with non-ESBL urosepsis (7/58 [12.1%] versus 4/118 [3.4%]; p = 0.042). Conclusions: Institution-specific data support prompt recognition of patients at risk for ESBL infections. Chronic renal insufficiency, recent travel to regions endemic for ESBL-producing organisms, primary language of Punjabi or Hindi, and male sex were the strongest risk factors for ESBL urosepsis at the study centre. However, findings from this single-centre study may not be generalizable to other institutions.