Characteristics of first urinary tract infection in children identified

April 29, 2011

Results of a prospective clinical and imaging study delineate the characteristics and clinical evolution of first urinary tract infection (UTI) in children with fever.

Results of a prospective clinical and imaging study delineate the characteristics and clinical evolution of first urinary tract infection (UTI) in children with fever.

Study results published in the Pediatric Infectious Disease Journal also demonstrated the value of renal ultrasonography as a screening tool for UTI.

Belgian researchers prospectively followed 209 children (median age, 10 months) who were treated for a first episode of febrile UTI in a hospital emergency department. Median follow-up time was 20 months. Urine samples were collected from all febrile children admitted with a high suspicion of UTI. Children were treated according to a predefined local antibiotic protocol, and all underwent renal ultrasound and voiding cystourethrography examinations.

Of the children included in the study, 132 (63%) were girls, and 157 (75%) had their first UTI before the age of 2 years. Escherichia coli was the most common causative agent, isolated in 189 (91%) of cases. Resistance to ampicillin and trimethoprim/sulfamethoxazole among E coli isolates was high-58% and 36%, respectively.

In 170 (81%) children, no structural abnormality was found on renal ultrasonography. Vesicoureteral reflux (VUR) was seen on voiding cystourethrography in 53 (25%) children; in 45 (85%) of the cases, it was mild. Of the 53 children with VUR, only 18 (34%) had an abnormal renal ultrasound examination. The researchers attribute this to the low sensitivity of renal ultrasound for detecting low-grade reflux.

Only 23 (11%) of children had relapses during follow-up. In 12 (52%) children, the urinary tract was normal on imaging work-up.

Overall, the performance of renal ultrasound to detect significant uropathies, except for low-grade VUR, was excellent, with a sensitivity of 97% and specificity of 94%. Use of ultrasound as a screening tool allows the avoidance of unnecessary voiding cystourethrography studies, the researchers conclude. The presence or absence of abnormal ultrasound findings is the key factor in deciding on whether VUR studies are needed.

Ismaili K, Wissing KM, Lolin K, et al. Characteristics of first urinary tract infection with fever in children. A prospective clinical and imaging study. Pediatr Infect Dis J. 2011;30(5):371-374.