Risk factors and long-term outcomes of febrile urinary tract infections in infants: A 10-year retrospective study

Purpose: The aim of this study is to report the outcomes of infants with febrile urinary tract infections (UTIs) and their associations with various risk factors. Materials and methods: This is a retrospective study of ≤2-year-old infants with recurrent febrile UTIs who underwent voiding cystourethrography (VCUG) in 2 referral hospitals from April 2011 to May 2020. Physical examinations included neurological examinations and external genital examination. Four-hour observation was performed, and postvoid residual volumes were recorded. Intermittent voiding during the observation period or sphincter dyscoordination during VCUG with/without constipation are considered high risk factors for bladder bowel dysfunction (BBD). Early treatments for BBD include laxatives, encouragement of toilet training, and awaiting maturation of bladder function. Results: Of the 102 infants enrolled, 36 were excluded: 6 with <30 months of follow-up and 30 that did not undergo VCUG. The rate of recurrent UTIs was 36.4% (24/66). High-grade vesicoureteral reflux (VUR) and bilateral VUR were observed in 58.5% and 26.8% patients, respectively. VCUG was performed twice in 41 patients. Among the 27 patients and 38 kidneys with initial VUR, 19 (70.4%) by person and 26 (68.4%) by renal unit experienced spontaneous resolution during follow-up ( P < 0.001). Univariate and multivariate logistic analysis revealed that none of the known risk factors such as phimosis and VUR are risk factors for recurrent UTIs. Conclusion: If BBD can be managed early as possible, VUR is not a significant risk factor for recurrent UTIs. The cohort in this study showed a high spontaneous resolution rate of high-grade VUR in infants with febrile UTIs.