Impact of untreated positive urine culture on urinary tract infections after cystoscopy.

Introduction: Cystoscopy is the most commonly performed urological examination during consultation. Various guidelines outline the benefits of performing urine culture before cystoscopy. The main objective of this study was to evaluate the impact of untreated positive urine cultures before cystoscopy on post-interventional urinary tract infection (UTI) rate. The secondary objectives were to identify factors favoring UTI and analyze the correlation between bacteria found before and after cystoscopy.

Methods: All patients who underwent cystoscopy in our hospital from November 2020 to March 2022 were included. Pregnant women and patients under antibiotic therapy were excluded. A urine culture was collected on the examination day, and the patients filled out a questionnaire one month later, indicating symptom occurrence. The primary outcome was UTI in the month following cystoscopy, defined according French Society for Infectious Diseases (SPILF) criteria by the presence of fever or at least one lower urinary tract symptom (pollakiuria, burning sensation during urination, urgent urination) and a positive uroculture (defined by SPILF criteria).

Results: The study included 410 patients. A positive pre-cystoscopy uroculture was noted in 80 (19.5%) patients. Factors significantly associated with UTI were a positive pre-cystoscopy urine culture (11% vs. 1.5%, OR=7.64 [2.44-23.9]) and the presence of voiding LUTS (8.5% vs. 1.9%, OR=4.42 [1.39-13.05]). Age, sex, the presence of a urethral catheter, and cystoscopy indication were not significantly associated with UTI. Only one patient, in the positive uroculture group, was hospitalized. For five patients, the microorganism found in the post-cystoscopy urine culture was the same as that identified in the pre-cystoscopy urine culture, with the same resistance profile on the antibiograms. The number needed to treat to prevent one UTI is 16.

Conclusion: Bacteriuria is associated with a higher UTI rate after cystoscopy. Nevertheless, the benefit of treating a positive uroculture before cystoscopy remains unclear.