Treatment duration of complicated urinary tract infections by extended-spectrum beta-lactamases producing enterobacterales

Background: Urinary tract infections caused by extended-spectrum beta-lactamase producing Enterobacterales (ESBL-EB) are a problem increasing in our clinical practice. Objectives: The aim of this study was to evaluate the clinical outcome in patients who received short (≤ 7 days) versus long courses (>7 days) of antimicrobial therapy for complicated ESBL-EB urinary tract infections. Methods: This is a retrospective and observational study. Positive urine cultures for ESBL-EB in our hospital between March 2015 and July 2017 were identified. Patients with complicated urinary tract infection were included. Differences between treatment groups (7 days or less vs more than 7 days) were analyzed according to baseline characteristics and severity of clinical presentation. Primary outcome was all cause 30-day mortality. Secondary outcome was a combined item of all cause mortality and reinfection by the same enterobacteria at 30 days. Results: 273 urine cultures were positive for ESBL-EB during the study period. 75 episodes were included, 40 in the long treatment group and 35 in the short treatment group. Mean treatment duration in short and long treatment groups was 6,1 and 13,8 days respectively. Mortality at 30 days was 5,7% in the short treatment group and 5% in the long treatment group without significant differences (P = 0,8). Mortality or reinfection by the same ESBL-EB at 30 days was 8,6% in the short treatment group and 10% in the long treatment group, without significant differences (P = 0,8). Conclusions: Short courses of antimicrobial treatment seems to be effective as treatment of complicated urinary tract infections by ESBL-EB.