Recurrent Urinary Tract Infections Due to Bacterial Persistence or Reinfection in Women: Does This Factor Impact Upper Tract Imaging Findings? A Quality Improvement Project

BACKGROUND: It is recommended that women with recurrent urinary tract infections (RUTIs) due to bacterial persistence (same strain) undergo upper urinary tract imaging to evaluate for sources of their infection. OBJECTIVE: To compare the rate of upper tract imaging abnormalities between RUTIs due to bacterial persistence or reinfection. METHODS: Following IRB approval, a prospectively maintained database of women with documented RUTIs (≥ 3 UTI/year) and trigonitis was reviewed for demographic data, urine culture findings, and radiology-interpreted upper tract imaging study (renal ultrasound (US), CT scan, IVP) findings. Patients with irretrievable images, absent or incomplete urine culture results for review, no imaging study performed, an obvious source for RUTI, or history of pyelonephritis were excluded. RESULTS: From 2006 to 2014, 116 of 289 women with symptomatic RUTIs met inclusion criteria. Mean age was 65.0±14.4 with 95% being Caucasian and 81% post-menopausal. Nearly one-third were sexually active and none has prolapse >stage 2. Forty-one percent (48/116) had persistent and 59% (68/116) had reinfection RUTI. Imaging studies included US (52), CT (26), US and CT (31), and IVP with US/CT (7). Of total imaging findings (N=58 in 55 women), 57/58 (98%) were noncontributory. One case (0.9%) of mild hydronephrosis was noted in the persistent RUTI group but not related to any clinical parameters. Escherichia coli was the dominant bacteria in both persistent (71%) and reinfection (47%) RUTI in most recently reported urine culture. CONCLUSION: This study reaffirms that upper tract imaging is not indicated for bacterial reinfection RUTI. However, the same conclusion can be extended to RUTI secondary to bacterial persistence, thus questioning the routine practice of upper tract studies in Caucasian post-menopausal women with RUTI and trigonitis.