Risk factors for kidney damage in pediatric patients with recurrent urinary tract infections

Abstract

Introduction: Urinary tract infection is a common pathology which can cause scarring and kidney damage, leading to future complications, such as hypertension and chronic kidney disease. Objective: To identify the predictive risk factors for kidney damage in children with recurrent urinary tract infection (ITUR). Methods: This was a retrospective, cohort study of patients <10 years with ITUR, who consulted as outpatients at the Social Security Institute Hospital and private clinics from January 2015 to July 2017. For our statistical analysis, patients were categorized in two groups according to whether or not they presented kidney damage. The correlation between kidney damage and age, sex, number of urinary tract infection episodes and the presence of vesicoureteral reflux (VUR) was established. For each variable, the relative risk (RR) with a confidence interval of 95% was calculated using Microsoft Excel 2010. Results: 112 patients presented ITUR, the average age was 41.8 months (SD: +/- 38.1), M/F ratio: 1:6. The average number of episodes of UTI per patient was 3.5 (SD +/- 1.9). 82/112 (73.2%) had sphincter control and 30/112 (26.7%) did not. Constipation, urinary urgency, incontinence, urinary retention were reported concomitantly in 38%, 48%, 33% and 20% of patients, respectively. The pathologies associated with ITUR were: lower urinary tract dysfunction in 45.5%, vesicoureteral reflux in 37% and hypercalciuria in 16.7%. The sensitivity and specificity of ultrasound to diagnose VUR were 22.7% and 87% respectively. 27/112 (24%) presented kidney damage. The factors associated with kidney damage were age <12 months (p = 0.027, OR 1.2-9, RR 2.2 (95% CI 1.1-4)), > 2 episodes of UTI (p = 0.0005, OR 1.9-12, RR 3.2 (IC95% 1.6-6.5) and VUR of Grade III or greater (p = 0.0000003, OR 4-32, RR 6 (95% CI 2, 7-14). Conclusions: 1 out of every 4 children with ITUR presents renal damage, an age <1 year, presence of 2 or more episodes of ITUR and VUR grade III or greater were risk factors associated with kidney damage.