Recurrent Urinary Tract Infections Due to Bacterial Persistence or Reinfection in Women-Does This Factor Impact Upper Tract Imaging Findings?

ABSTRACT

PURPOSE: We compared the rates of upper tract imaging abnormalities of recurrent urinary tract infections due to bacterial persistence or reinfection. MATERIALS AND METHODS: Following institutional review board approval we reviewed a prospectively maintained database of women with documented recurrent urinary tract infections (3 or more per year) and trigonitis. We searched for demographic data, urine culture findings and findings on radiology interpreted upper tract imaging, including renal ultrasound, computerized tomography or excretory urogram. Patients with irretrievable images, absent or incomplete urine culture results for review, no imaging performed, an obvious source of recurrent urinary tract infections or a history of pyelonephritis were excluded from analysis. RESULTS: Of 289 women from 2006 to 2014 with symptomatic recurrent urinary tract infections 116 met study inclusion criteria. Mean ± SD age was 65.0 ± 14.4 years. Of the women 95% were white and 81% were postmenopausal. Almost a third were sexually active and none had prolapse stage 2 or greater. Of the 116 women 48 (41%) had persistent and 68 (59%) had reinfection recurrent urinary tract infection. Imaging included ultrasound in 52 patients, computerized tomography in 26, ultrasound and computerized tomography in 31, and excretory urogram with ultrasound/computerized tomography in 7. Of the total of 58 imaging findings in 55 women 57 (98%) were noncontributory. One case (0.9%) of mild hydronephrosis was noted in the persistent recurrent urinary tract infection group but it was not related to any clinical parameters. Escherichia coli was the dominant bacteria in 71% of persistent and 47% of reinfection recurrent urinary tract infections in the most recently reported urine culture. CONCLUSIONS: This study reaffirms that upper tract imaging is not indicated for bacterial reinfection, recurrent urinary tract infections. However, the same conclusion can be extended to recurrent urinary tract infections secondary to bacterial persistence, thus, questioning the routine practice of upper tract studies in white postmenopausal women with recurrent urinary tract infections and trigonitis.