Identification of Probable Urinary Tract Infection in Children Using Low Bacterial Count Thresholds in Urine Culture.

Objectives: To assess the proportion of children, symptomatic for urinary tract infection (UTI), with urine culture showing single bacterial species >10⁴ CFU/mL, and to compare patient and disease characteristics between children having low counts (from >10⁴-10⁵ CFU/mL) and those with counts >10⁵ CFU/mL. Methods: Prospective observational study, enrolling symptomatic children aged 1 month to 12 years. Mid-stream clean-void or catheter collected urine were cultured. Children with single species >10⁴ CFU/mL were scheduled for imaging studies, following age criteria of Indian Society of Pediatric Nephrology guidelines. The main outcome was proportion with single bacterial species >10⁴ CFU/mL in urine culture. Results: Of 216 children (132 males) with median (IQR) age of 24 (12, 48) months, 38 (17.6%) showed single species growth >10⁴ CFU/mL. Of these, 29 (13.4%) were diagnosed as UTI at cutoff >10⁵ CFU/mL, and an additional 9 (4.2%) were found to have 'probable low-count UTI' (from >10⁴ to 10⁵ CFU/mL). One child in the latter group had bilateral hydroureteronephrosis, vesico-ureteral reflux and renal scarring. There was largely no difference in parameters between children with low counts and those with counts >10⁵ CFU/mL. Conclusion: An additional proportion of symptomatic children with probable urinary tract infection and possible underlying urological abnormalities may be identified by lowering bacterial colony count cutoff to >10⁴ CFU/mL, in clean-voided and catheter-based urine samples. [ABSTRACT FROM AUTHOR]