[Bacterial urovirulence factors and their association with functional and anatomical abnormalities and recurrence of urinary tract infections in children]. / Factores de urovirulencia bacteriana: asociación con recurrencias y anomalías anatómicas y funcionales en niños con infección del tracto urinario.

BACKGROUND: Urinary tract infections in children are associated with functional and anatomical abnormalities of the urinary tract, they tend to recur and can cause permanent kidney damage. AIM: To study in children with urinary tract infections, microbiological factors associated to recurrence, functional and anatomical abnormalities of the urinary tract. PATIENTS AND METHODS: A prospective sample of children was incorporated into a follow-up protocol after their first episode of bacteriologically-demonstrated urinary tract infection. In all patients an abdominal ultrasound examination and a mictional urethrocystography were done and the presence of fimbriae was studied in isolated strains of Escherichia coli. RESULTS: Two hundred fifteen cases bad an adequate adherence to the study protocol, 190 caused by E coli. Fimbriated E coli strains were isolated with greater frequency from children with pyelonephritis than from those with a low urinary tract infection (50 and 28% respectively). The absence of fimbriae in E coli strains was associated with a higher risk of recurrent infections (odds ratio = 3, confidence intervals = 2-9.2) and an abnormal urethrocystography (odds ratio = 3, confidence intervals = 1.1-10.2). CONCLUSIONS: These data are consistent with foreign reports and support the need to study adhesins in E coli strains isolated from children with urinary tract infections.