Urine flow cytometry is an adequate screening tool for urinary tract infections in children
Diagnosing a urinary tract infection in children is often difficult due to non-specific symptoms and requires invasive and time-consuming procedures. Flow cytometry is a new and rapid method of analyzing urine to confirm or exclude UTIs. We have investigated the sensitivity and specificity of urine flow cytometry (Sysmex UF1000i) compared to conventional diagnostic techniques in a prospective study from January 1, 2014 until January 1, 2015. All children under 13 years of age with a suspicion of urinary tract infection were screened using both urine flow cytometry and urine culture. A urinary tract infection was defined as the combination of leukocyturia (≥ 25 leukocytes per μl) and a positive urine culture in the presence of clinical symptoms. A total number of 412 urine samples were collected, of which 63 cases (15.3%) were positive for a urinary tract infection. Receiver operating characteristic analysis showed an area under the curve of 0.97 (95% confidence interval h0.93–1.00) for the bacterial count. When using a cut-off value of 250 bacteria/μl in the presence of leukocyturia, the sensitivity for urinary tract infection is 0.97 with a negative predictive value of 97%, and the specificity is 0.91 with a positive predictive value of 90%.
What is known
• Screening for urinary tract infections in children is difficult due to invasive and time-consuming procedures.
• There is both over- and under-treatment of urinary tract infections due to the delays in accurate diagnosing.
What is new
• Flow cytometry is a rapid and accurate method to provide useful information in the diagnosis of urinary tract infection in children. When negative, flow cytometry can exclude urinary tract infection in children with a high degree of confidence. When flow cytometry is positive, the possibility of a urinary tract infection in children is increased.
KeywordsUrinary tract infection Urine flow cytometry Children Screening
Area under the curve
Colony forming units
Receiver operating characteristic
Urinary tract infection
M. Broeren participated in the study design analysis and especially the statistical analysis, and writing the manuscript.
R. Nowacki participated in the study design analysis, patient inclusion and writing the manuscript.
F. Halbertsma participated in the study design, patient inclusion, analysis and writing the manuscript.
N. Arents participated in the micribiological analysis, and writing the manuscript.
S. Zegers participated in the study design analysis the statistical analysis, and writing the manuscript especially related to clinical relevance.
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