Introduction: Though septic stones are well-recognized as a medical emergency, patients with uncomplicated renal colic (without systemic inflammatory responses or renal impairment) and positive urine cultures (UC) pose a dilemma in management considerations. Therefore, the objective of this study was to: 1) assess the rate of ‘incidental’ positive urine cultures in patients with ureteral stones referred to our stone clinic; and 2) determine the risk of infectious adverse events (IAE) in patients with ureteral stones and positive urine cultures.

Methods: A retrospective chart review was performed for all acute stone clinic referrals between November 10, 2019, and October 1, 2020. Urgent referrals necessitating immediate intervention were excluded. Demographics, investigations, procedures, unscheduled visits, and IAE were all documented. Descriptive statistics were used to group patients based on their UC.  

Results: Over the study period, 1029 patients were identified and 35.4% (n=374) of them had UC drawn at presentation. Of the 655 patients without UC, 0.6% (n=6) eventually developed sepsis and required urgent renal decompression. Most (87%, n=333) UC completed at presentation were negative (no growth or mixed flora), and none of these patients went on to have an IAE. Of the 13% of UCs that were positive (n=39), only two IAEs (5.13%) were identified, 2–30 days after initial presentation. Both patients had normal acute phase reactants (white blood cells, C-reactive protein) and a history of recurrent urinary tract infections.   

Conclusions: Approximately one-third of patients referred to our acute stone clinic had UC at presentation, with an overall delayed IAE rate of 0.7%. Of those with positive UC, only 5% experienced an IAE, suggesting conservative management may be a reasonable consideration in this patient population.