Recurrence risk in infants with urinary tract infections and a negative radiographic evaluation.

Purpose: Infants with urinary tract infections (UTI) and no abnormality on radiological evaluation are usually discharged from urological followup but the natural history of these children is unknown. We evaluate the rate of and potential risk factors for UTI recurrence in this specific population.

Materials And Methods: We reviewed retrospectively charts of children evaluated for first UTI before age 6 months between January 1996 and February 2001. Only patients with a normal ultrasound and voiding cystourethrogram were included in this study. A telephone questionnaire was administered to the parents, which inquired about the UTI, duration of breast-feeding, type of formula, family history of UTI, neurological problems, history of constipation or recurrent fevers, as well as social status. Chi-square test was performed for statistical analysis.

Results: We identified 264 children with UTIs, of whom 119 (45%) had a negative ultrasound and voiding cystourethrogram. Followup was available on 68 girls (81%) and 16 boys (19%) of the 119 children (71%). Of the 84 children 16 (19%) had recurrent UTI. Mean followup was 4.4 years (range 1.9 to 7.0). No factors had a statistically significant correlation for UTI recurrence. The p value for gender and history of undiagnosed fevers was 0.077 and 0.082, respectively.

Conclusions: About 20% of children will have recurrent UTIs despite negative radiological evaluation. Although not statistically significant, there was a trend for an increased risk in girls and those with recurrent febrile illnesses. History of daytime dryness and/or constipation was not predictive of recurrent UTIs in our series.