Screening performance of the MUS-3600 urine analyzer for urinary tract infection: comparison with urine culture

Urine culture is the gold standard for diagnosing urinary tract infections (UTIs), but most samples yield negative results. A rapid and accurate screening method could accelerate reporting, reduce workload, and lower costs. This study aimed to evaluate the diagnostic performance of the MUS-3600 urine analyzer as a screening tool for UTIs.

Urine samples submitted to the microbiology laboratory were analyzed using the MUS-3600 within 10 min of collection. The analyzer uses flow-type micro-imaging and artificial intelligence-based particle classification. Culture results with ≥10⁴ CFU/mL were defined as positive; lower counts were negative.

For white blood cells (WBC, >39/μL), sensitivity, specificity, PPV, NPV, and elimination rate were 63.4%, 84.5%, 50.8%, 90.1%, and 67.5%, respectively. Bacilli (>103/μL) showed 62.1%, 88.1%, 56.9%, 90.2%, and 70.4%. Suspected cocci (>859/μL) demonstrated lower accuracy (44.4%, 78.7%, 34.5%, 84.9%, and 62.8%). Combining WBC and bacilli yielded the highest elimination rate (77.2%) and NPV (87.9%). The analyzer performed better in males (NPV 93.9%) than in females (NPV 82.1%).

The MUS-3600 provides moderate accuracy for UTI screening and may help reduce unnecessary urine cultures, particularly in male patients. However, its limited sensitivity, especially for cocci, prevents its use as a stand-alone screening tool. Further studies are needed to confirm its role as a complementary method for culture elimination.