Low yield from imaging after non urine tract infections in children treated in primary care and emergency department.

Background: Imaging is recommended for selected children following urinary tract infections (UTIs) to look for actionable structural abnormalities. Non is considered high risk in many national guidelines, but evidence is mainly drawn from small cohorts from tertiary centres.

Objective: To ascertain imaging yield from infants and children <12 years diagnosed with their first confirmed UTI (pure single growth >100 000 cfu per ml) in primary care or an emergency department without admission stratified by bacteria type.

Design, Setting, Patients: Data were collected from an administrative database of a UK citywide direct access UTI service between 2000 and 2021. Imaging policy mandated renal tract ultrasound and Technetium-99m dimercaptosuccinic acid scans in all children, plus micturating cystourethrogram in infants <12 months.

Results: 7730 children (79% girls, 16% aged <1 year, 55% 1-4 years) underwent imaging after first UTI diagnosed by primary care (81%) or emergency department without admission (13%). UTI yielded abnormal kidney imaging in 8.9% (566/6384). and KPP (, , ) yielded 5.6% (42/749) and 5.0% (24/483) with relative risks 0.63 (95% CI 0.47 to 0.86) and 0.56 (0.38 to 0.83)), respectively. No difference was found when stratified by age banding or imaging modality.

Conclusion: In this largest published group of infants and children diagnosed in primary and emergency care not requiring admission, non UTI was not associated with a higher yield from renal tract imaging.