Risk Factors of Breakthrough Urinary Tract Infection in Children with Primary Vesicoureteral Reflux

Objective: Vesicoureteral reflux (VUR) is a significant risk factor for urinary tract infections (UTI) in children, potentially leading to renal damage. Antibiotic prophylaxis is essential for the pediatric patients with VUR aiming to reduce the chance of UTI. However, breakthroughs UTI can occurred despite adequate prophylactic antibiotics. We aimed to identify the factors contributing to breakthrough UTIs in the patients with VUR.Material and Methods: This retrospective study analyzed medical records from 238 children with primary VUR from 2000-2019. This study included children aged less than 10 years old at the time of VUR diagnosis and excluded those with secondary VUR, incomplete medical records, or lost to follow-up. Univariate and multivariate analyses were utilized to determine the predictors of breakthrough UTIs.Results: This study comprised 238 children diagnosed with VUR, including 133 males and 105 females; 86 patients experienced a breakthrough infection. Multivariate analysis revealed that each additional UTI before prophylactic antibiotics significantly increased the likelihood of breakthrough infections (OR 1.62; 95% CI 1.10-2.37; p-value=0.013). Upper pole renal scarring and generalized abnormal renal scans were also significant risk factors with OR 5.57; 95% CI (2.16-14.40); p-value<0.001 and OR 5.19; 95% CI (1.36-19.75); p-value=0.016, respectively. Bowel bladder symptoms emerged as a substantial risk factor (OR 30.16; 95% CI 1.43-633.86; p-value=0.028), whereas the use of cephalexin appeared protective (OR 0.22; 95% CI 0.05-0.94; p-value=0.042).Conclusion: The number of UTIs before prophylaxis antibiotics, abnormal renal scan at the upper pole and generalized kidney and bowel bladder symptoms were independent risk factors for breakthrough infections. Moreover, the study showed that the use of cephalexin was a statistically significant protective factor against breakthrough UTI.