The prevalence of resistant urinary tract infections is increasing

13.09.2018

The Urinary Tract Infections acquired in the community that are caused by resistant ESBL-producing Enterobacteriaceae are increasing worldwide. In the current study, the proportion of Urinary Tract Infections caused by these pathogens was investigated among patients seen at an urban Emergency Department.

Approximately 6% of all patients presenting at an emergency department (ED) during a 1-year period with a urinary tract infection (UTI) were diagnosed with an extended-spectrum b-lactamase (ESBL)-producing Enterobacteriaceae infection, according to new findings published in the Annals of Emergency Medicine. Many of these patients also lacked an identifiable risk factor for a multidrug-resistant UTI and had frequently been treated with discordant antimicrobial agents.

During a 1-year period, a total of 1045 patients diagnosed with a UTI were seen in the ED, and in this group, 62 ESBL-producing isolates (5.9%; 95% CI, 4.6%-7.5%) were identified. Some of the characteristics of this patient subgroup included: median age 50 years, 37 (60%) were women, 28 (44%) were Hispanic, 11 (18%) had been hospitalized in the previous 3 months, 19 (31%) had pyelonephritis, 49 (79%) isolates were Escherichia coli, 44 (71%) were levofloxacin resistant, and 24 (23%) were nitrofurantoin resistant. The initial course of antibiotic therapy was discordant with the isolate's susceptibility in nearly half of the participants, 26 of 56 cases (46%; 95% CI, 33%-60%). The initial oral antibiotic prescribed was also discordant in 19 of 41 cases (46%; 95% CI, 31%-63%). A total of 27 of the UTIs (44%; 95% CI, 31%-57%) were categorized as community associated; 8 women in this subgroup were younger than 50 years of age, had no comorbidities, and had not experienced more than 1 UTI during the previous year. Of 12 community-associated E coli isolates tested, all were confirmed as harboring ESBL genes.

The results raise serious concern in regard to trends in antibiotic resistance among uropathogens from community-onset infections, and have implications for future ED practice and research. In some locations in the United States, "fluoroquinolone resistance rates in urinary isolates already exceeds the 20% level at which this class should not be used. To address this concern, wide use of urine culture even in uncomplicated cystitis, combined with a reliable follow-up system should be done.

Reference

Frazee BW, Trivedi T, Montgomery M, Petrovic DF, Yamaji R, Riley L. Emergency department urinary tract infections caused by extended-spectrum β-lactamase-producing enterobacteriaceae: many patients have no identifiable risk factor and discordant empiric therapy is common [published online July 3, 2018]. Ann Emerg Med. doi: 10.1016/j.annemergmed.2018.05.006