Enhancing clinical decision-making: Sysmex UF-5000 as a screening tool for bacterial urinary tract infection in...

Area of Science:

• Clinical diagnostics
• Pediatric infectious diseases
• Microbiology

Background:

• Urinary tract infections (UTIs) in children require rapid screening tests to inform clinical decisions.
• Current methods often necessitate lengthy urine cultures, delaying diagnosis and treatment.
• A need exists for efficient tools to avoid unnecessary cultures and expedite patient care.

Purpose of the Study:

• To evaluate the Sysmex UF-5000 flow cytometer as a screening tool for UTIs in pediatric patients.
• To assess the analyzer's performance in detecting white blood cells (WBC) and bacteria (BACT) compared to urine culture results.
• To determine the utility of the UF-5000 in identifying negative cultures and significant bacterial growth.

Main Methods:

• Analysis of 4445 pediatric urine samples collected between January 2020 and September 2023.
• Measurement of urine WBC and BACT counts using the Sysmex UF-5000 flow cytometer.
• Comparison of UF-5000 findings with standard urine culture results to assess diagnostic accuracy.

Main Results:

• Optimal cut-offs for positive cultures were BACT at 92.2/μL (AUC: 0.944) and WBC at 40.8/μL (AUC: 0.863).
• A BACT cut-off of 7.8/μL achieved a 0.9% false negative rate, enabling avoidance of 28.1% of unnecessary cultures.
• The UF-5000 demonstrated higher consistency for Gram-negative (90.3%) than Gram-positive (86.8%) bacteria, with superior concordance for significant bacterial growth.

Conclusions:

• The Sysmex UF-5000 shows promise for screening pediatric urine cultures, identifying negative results and significant bacterial growth.
• The analyzer aids in reducing unnecessary cultures and can guide empirical antibiotic therapy, especially for Gram-negative UTIs.
• Performance may vary by study population, but Gram typing capability enhances clinical decision-making.