BACKGROUND: The incidence of urinary tract infections (UTIs) after voiding cystourethrogram (VCUG) varies widely in the literature with a reported range of 0-13% in patients on some form of antibiotics to 7-42% in patients without. However, these are studies in which urine cultures (UCx) were obtained after VCUGs were done when lower urinary tract symptoms and/or fevers developed. Our institution obtains routine urine cultures (UCx) on every patient undergoing outpatient VUCG. We sought to identify the incidence of asymptomatic bacteriuria and the risk factors for the development of UTI within 14 days after VCUG in the largest cohort of pediatric patients in the literature. METHODS: We retrospectively identified all VCUG studies between 1/2017 to 12/2022. Only outpatient VCUG with a urine culture on the same day were included. Those over 18 years of age were excluded. Demographic data, comorbidities, indications for the study, imaging data, urine culture results were collected and analyzed.
RESULTS: A total of 1705 VCUG studies were identified. Median age at the time of study was three years. 60% were female and 40% were males. 25% of patients had positive urine cultures. Within 14 days of the study, among those with a positive urine culture, 43% were prescribed antibiotics, 16% experienced urinary tract symptoms (dysuria, pelvic pain, frequency, urgency, hematuria), 7.3% developed a fever and 3.5% were hospitalized. Multivariate analysis showed spina bifida, anorectal malformation, history of recurrent UTIs, CIC use, previous bladder surgeries were risk factors for having a positive urine culture. However, only CKD, history of recurrent UTIs, and previous ureteral surgeries were found to be risk factors for the development of clinical UTI symptoms. Statistically significant odds ratio for development of asymptomatic bacteriuria and UTI are listed in table 1. The presence of WBCs, leukocyte esterase and nitrite on UAs were not predictive for symptom development. Interestingly, 77% of antibiotic prescriptions were by pediatric urologists.
CONCLUSIONS: While our study shows a positive urine culture rate of 25% after VCUG studies, the rate of symptomatic UTI is only 3.8%. Of those with a positive urine culture, nearly half received antibiotics. Our findings also showed that UAs are not helpful in predicting symptomatic UTIs and only select patients with risk factors would benefit from a urine culture at the time of VCUG to avoid over-testing patients and over-treatment of asymptomatic bacteriuria.
