UF-100尿液分析仪细菌计数对泌尿道感染的诊断性能评价

Evaluation of the bacterial count on a UF-100 automated urine analyzer for diagnosing urinary tract infection

目的:对UF-100尿液分析仪细菌计数结果进行诊断性能评价。方法:360例门诊与住院患者经初诊疑为泌尿道感染者的清洁中段晨尿先作细菌培养,然后尽快在UF-100尿液分析仪上检测细菌数及白细胞数。结果:以中段尿细菌培养结果为标准对UF-100尿液分析仪细菌数进行评价,ROC曲线下面积为0.895,细菌数的阳性阈值为≥3227/μL,敏感性为83.3%,特异性为83.3%,假阳性率为31.8%,假阴性率为7.8%,准确率为83.3%。将细菌计数和WBC数联合进行评价时,敏感性为81.5%,特异性为90.1%,假阳性率为22.1%,假阴性率为8.1%,准确率为87.5%。结论:UF-100尿液分析仪细菌计数与泌尿道感染诊断标准有较好的一致性,但有一定的漏检率,结合白细胞计数可作为临床泌尿道感染早期诊断的实验室检查指标之一。

Objective To assess the diagnostic value of the bacterial count on a UF-100 urine analyzer. Methods Bacterial culture of clean-catch midstream urine was performed in 360 patients suspicious for urinary tract infection （UTI）, then the bacterial count and leukocyte count were detected by a UF-100 urine analyzer. Results Using the outcomes of bacterial culture of midstream urine as criteria, we assessed the bacterial count on the analyzer. The area under the ROC curve was 0.895; the positive cut-off value of bacterial count was ≥3 227/txL. The sensitivity of bacteria count for diagnosing UTI was 83.3%, the specificity 83.3%, the false-positive rate 31.8%, the false-negative rate 7.8%, and the accuracy 83.3%. As bacterial count was combined with leukocyte count, the sensitivity, specificity, false-positive rate, false-negative rate, and accuracy were 81.5%, 90.1%, 22.1%, 8.1%, and 87.5%, respectively. Conclusions The bacterial count detected by the UF-100 urine analyzer shows good agreement with the laboratory criteria for the diagnosis of UTI but has a rate of misdiagnosis. Bacterial count combined with leukocyte count can be used as one of the indices for the early diagnosis of the disease.