Urinary Tract Infection Diagnosis—A Companion to the American Academy of Pediatrics’ 2026 Clinical Practice Guideline on the Diagnosis and Management of Urinary Tract Infection: Technical Report

Accurate diagnosis is essential to appropriate care. Although urinary tract infection (UTI) is one of the most common bacterial infections in children, there is no gold standard for its diagnosis. During the American Academy of Pediatrics' revision of its Clinical Practice Guideline for the Diagnosis and Treatment of Urinary Tract Infection in Children from Eight Days to Five Years of Age, the Guideline panel established a revised UTI definition through an iterative discussion process. This article details the rationale behind those revisions. The definition of UTI is based in three domains: symptoms, signs of inflammation, and culture results. The panel focused the revision of the definition in the domains of inflammation and culture results. Although there is controversy in the literature regarding the inclusion of pyuria in the definition of UTI, current literature also supports that, in most clinical scenarios, pyuria is present in a UTI and should be included as a diagnostic criterion. Thus, the panel agreed that the UTI definition should include pyuria as a diagnostic criterion, and identified separate thresholds based on age and whether urine cultures results are available or pending. The other major domain where the panel closely examined the evidence was culture results. In accordance with the updated literature base, the panel modified the definition for positive culture on the basis of age and method of urine collection. The panel's goal in developing the new UTI definition was to use currently available evidence to optimize management of children with UTI by avoiding overdiagnosis and overtreatment, while minimizing the number of missed diagnoses and delaying treatment.