Examining the Recurrence of Urinary Tract Infections in Children With a History of Acute Pyelonephritis

Background: Recurrence of urinary tract infection (UTI) is common. Renal scar develops in 3% to 15% of patients following acute pyelonephritis (APN). Vesicoureteral reflux (VUR) is the most common risk factor for both conditions. Objectives: This study defines the rate of recurrent UTIsin specific groups of children presented by APN. The secondary outcome was determining the frequency of renal scarring. Methods: A cross-sectional study was performed in children ≤18 years old with APN. Patients with normal kidney ultrasound and normal voiding cystourethrogram (VCUG) were enrolled. The roles of gender, age at first APN, and abnormal bladder ultrasound findings were evaluated as risk factors for the recurrence of UTIs and renal scarring. In addition, the role of chronic constipation in the recurrence of UTIs was considered. P<0.05 associated with an odds ratio >1 were considered risk factors. Results: In total, 139 cases with a median age of 26 months were enrolled, including 94.2% of girls. The frequency of renal scarring was assessed in 28.8% of patients who underwent Tc99m-DMSA scan. Recurrent UTIs and renal scarring were found in 54% and 17.8% of patients, respectively. Gender, age at first pyelonephritis, and abnormal findings in bladder ultrasound were not risk factors for either recurrent UTI or renal scarring. In addition, chronic constipation was not a risk factor for recurrent UTIs. Conclusions: Recurrent UTI and renal scarring are common in children presented by APNs, even in the absence of VUR.