Factors associated with urinary tract infection after cystography in a contemporary pediatric population

Background: Cystography is a common genitourinary imaging study performed in the evaluation of children and can result in iatrogenic infection. Objective: We sought to determine the incidence of and factors associated with post-cystography urinary tract infection (PCUTI) in a contemporary population. Study design: A single-institution, retrospective review was performed for 913 patients who underwent cystography (voiding cystourethrogram, radionuclide cystography, and contrast-enhanced voiding urosonography). PCUTI was defined as strict (fever or symptoms + pyuria + positive urine culture) or pragmatic (met strict criteria or high clinical suspicion prompting treatment) within 30 days of cystography. A multivariate logistic regression model was used to adjust for the propensity of being on antibiotic prophylaxis. Results: By strict criteria, 1.0 % and 2.2 % of patients developed PCUTI within 7 and 30 days of cystography, respectively. An additional 13 patients (33 total, 3.6 %) met pragmatic criteria for 30-day PCUTI. Circumcised males were less likely than females (OR 0.24, 95 % CI 0.05–0.76, p = 0.030) and patients with kidney stones on ultrasound were more likely than those without stones (OR 12.2, 95 % CI 3.04–42.34, p < 0.001) to have PCUTI. Being on antibiotic prophylaxis was not associated with decreased odds for post-cystography urinary tract infection. Discussion: Based on our results, we can reasonably counsel families that circumcised males have lower likelihood of PCUTI, children with kidney stones on their ultrasound have higher likelihood of PCUTI, and prophylactic antibiotics did not reduce the likelihood of developing a PCUTI. This study is limited by our pragmatic definition of UTI and the variables included in our multivariate model. Conclusions: There is a relatively small but noteworthy risk for urinary tract infection after cystography. Sex, circumcision status, and presence of kidney stones on ultrasound were significantly associated with the likelihood of PCUTI, while antibiotic prophylaxis was not. Further investigation is necessary to determine interventions that may reduce PCUTI in high-risk patients.