Incidence and Risk Factors of Recurrent Urinary Tract Infections during Antibiotic Prophylaxis in Children with Primary Vesicoureteral Reflux

ABSTRACT

PURPOSE: Recurrent urinary tract infection(UTI) in primary vesicoureteral reflux(VUR) may lead to serious renal scarring, a major cause of childhood hypertension and end-stage renal disease. To prevent recurrent UTI, low-dose long-term antibiotic prophylaxis has been recommended. However, recurrent UTI still develops during antibiotic prophylaxis, the efficacy of which is now being disputed. The emergence of resistant bacteria has also raised concerns. To evaluate the effect of antibiotic prophylaxis, we investigated recurrent UTI during prophylactic antibiotic use in children with primary VUR. Materials:The incidence and risk factors of recurrent UTI were retrospectively evaluated in ninety-one children with primary VUR on trimethoprim-sulfamethoxazole(TMP/SMX) prophylaxis during the year following their index febrile UTI. RESULTS: Recurrent UTI occurred in 31.9%(29/91) children and comprised 0.32 episodes/ patient year. Febrile UTI was 0.26 episodes/patient year and afebrile UTI was 0.07 episodes/ patient year. The recurrent rate of UTI in male patients with phimosis was 37.2%(19/51), which was significantly higher than in males without phimosis 0%(0/5)(P=0.025). In the logistic regression analysis for recurrent UTI, renal scar was the significant risk factor for recurrent UTI [RR 3.8(95% CI 1.0-14.1) P=0.04]. For other well-known risk factors such as sex, age, degree of VUR, APN, and voiding dysfunction, the differences were not significant. CONCLUSION: TMP/SMX prophylaxis did not prevent recurrent UTI in children with primary VUR. Phimosis and renal scars were the risk factors for recurrent UTI but the grade of primary VUR was not. In VUR without phimosis and renal scar, a randomized controlled study without antibiotic prophylaxis is required.