Is There a Difference in the Contamination Rates of Urine Samples Obtained by Bladder Catheterization and Clean-Catch Collection in Preschool Children?

Abstract

The objective of this study was to compare contamination rates in urine samples obtained by transurethral catheterization and cleancatch methods in preschool children aged 2 to 5 years.Methods: A retrospective, chart review was performed on patients evaluated in our emergency department over a 6-month period who had a urine culture obtained by either transurethral catheterization or clean-catch methods. The charts were reviewed for urine bacterial colony counts and divided into positive, negative, or contaminated cohorts. Demographic data were collected as well.Results: Four hundred sixty patients met inclusion for this study. Of these patients, there were 120 samples collected by catheter (26.1%) and 340 samples collected by clean-catch method (73.9%).Female patients comprised 73% of the eligible samples (n = 336), and 27% were male (n = 124). Contamination rates significantly varied by collection method ( P < 0.0001), with only 9 contaminated catheter samples (7.5%) and 125 contaminated clean-catch samples (36.76%). Contaminated samples were found in 122 of 336 female urine samples (36.3%), and 12 of 124 male urine samples (9.7%). There were no associations found between contamination rates and age within either sex.Conclusions: Our study demonstrated a higher urine culture contamination rate in preschool age children in the clean-catch method group compared with the transurethral catheterization group. This finding was particularly strong within the female subset, which could partially be accounted for by the small male sample size.

Commentary: Serum Calprotectin Is a Valid Biomarker in Distinction of Bacterial Urinary Tract Infection From Viral Respiratory Illness in Children Under 3 Years of Age

“…Urine culture obtained by this method cannot be considered a "gold standard." Since the diagnosis of bacterial UTI in the published study is likely inaccurate, the statement of the commented article, with sensitivity and specificity of sCal identifying bacterial UTI from RI were 77.6 and 69.0%, respectively, is based on unreliable data (6)(7)(8)(9)(10)(11). Since bag urine specimens were used for urine collection, bacterial UTIs were likely overdiagnosed (1).…”