More Restrictive Definition Reduces UTI Prevalence in Bronchiolitis

By Will Boggs MD

January 31, 2019

NEW YORK (Reuters Health) - The prevalence of urinary tract infection (UTI) in children with bronchiolitis declines when UTI is narrowly defined, according to a systematic review and meta-analysis.

"With the inclusion of a positive urinalysis, the overall prevalence of UTI in bronchiolitis is below accepted testing thresholds, even in infants <2 months of age," Dr. Corrie E. McDaniel from Seattle Children's Hospital and the University of Washington told Reuters Health by email. "This can be useful in risk assessment and shared decision making with families."

Some studies have suggested that as many as 12% of infants with bronchiolitis have a concomitant UTI, but the diagnosis of UTI was defined by a positive urine culture alone, regardless of the urinalysis results, in many studies.

Dr. McDaniel and colleagues investigated the prevalence of UTI in infants with bronchiolitis when positive urinalysis results are incorporated into the UTI definition in their analysis of 18 bronchiolitis studies, included seven studies that reported both urinalysis data and urine culture positivity.

Several studies presented urinalysis data but did not define a positive urinalysis result, and there was no consistency in the definition of a UTI when stratified based on studies that provided urinalysis data versus those that did not.

The overall reported prevalence of UTI in bronchiolitis was 3.1% from all 18 included studies.

In the seven studies that provided urinalysis data, the prevalence of UTI not including urinalysis data was 2.2%, whereas the prevalence fell to 0.8% when a positive urinalysis result was included as a diagnostic criterion, according to the January 28th JAMA Pediatrics online report.

E. coli was the causative UTI pathogen in 63.9% of bronchiolitis cases. The weighted prevalence of E. coli increased to 80.3%, however, when applying the diagnostic criterion of a positive urinalysis result.

"The prevalence of UTI in infants with bronchiolitis is affected by UTI diagnostic criteria," the researchers conclude. "With the incorporation of a positive urinalysis result into the disease definition, the estimated prevalence of concomitant UTI is less than proposed thresholds for testing. Applying a positive urinalysis result as a diagnostic criterion for UTI may have the potential to decrease the misdiagnosis of UTI in infants with other recognizable clinical syndromes as well."

"Most investigations looking at the prevalence of UTI in other conditions look purely at urine culture positivity," Dr. McDaniel said. "Particularly in the youngest infants <2 months of age, further investigations using urinalysis criteria in conditions such as jaundice and BRUE (brief, resolved, unexplained events) may help not only to inform clinical decision making but potentially to reduce unnecessary antibiotic exposure."


JAMA Pediatr 2019.