发光二极管荧光显微镜实验室诊断效果评价

Evaluation of Light Emitting Diodes for Auramine O Fluorescence Microscopy in Detecting Mycobacterium tuberculosis

目的评估发光二极管荧光显微镜实验室诊断结核分枝杆菌的能力。方法收集409份痰标本，以固体罗氏培养为金标准，比较发光二极管荧光显微镜与普通光学显微镜、普通荧光显微镜在敏感性、特异性、阳性预测值、阴性预测值及检出时间上的差异，并比较技术人员对几种方法的评价。结果罗氏培养阳性的175份痰标本中，普通光学显微镜法112份为阳性，普通荧光显微镜法121份为阳性，发光二极管荧光显微镜法130份为阳性，敏感性分别为64．0％、69．1％、74．3％；罗氏培养阴性的234份痰标本中，普通光学显微镜法233份为阴性，荧光显微镜法227份为阴性，发光二极管荧光显微镜法227份为阴性，特异性分别为99．6％、97．0％，97．0％。χ^2检验统计结果表明，发光二极管荧光显微镜与普通光学显微镜、普通荧光显微镜检测结果差异显著（P〈0．001）。普通光学显微镜、普通荧光显微镜和发光二极管荧光显微镜读片所用的平均时间分别为186．7秒、75．1秒、72，2秒，发光二极管荧光显微镜与普通光学显微镜在读片时间上显著差异，与普通荧光显微镜差异不明显（P〈0．05）。参与研究的技术员评价发光二极管荧光显微镜较其他两种方法易接受。结论发光二极管荧光显微镜法较普通光学显微镜法及普通荧光显微镜在检查效果及检出时间上存在明显优势，对技术人员的亲和性最好，具有推广使用的价值。

Objective To assess the performance of light emitting diodes（LED） for auramine O fluorescence microscopic in screening Mycobacterium tuberculosis. Methods We compared the sensitivity, specificity,PPV,PNV, detection time of Ziehl-Neelsen（ZN）, conventional fluorescence microscopy（FM） and LED with solid L-J culture （L-J） as gold standard, we also checked the user-friendliness of three methods. Results Of the 175 L-J positive samples,112 samples are ZN positive,121 samples are FM positive,130 samples are LED positive, sensitivity are 64.0%,69.1%,74.3% respectively; Of the 234 L-J negative samples, 233 samples are ZN negative,227 samples are FM negative, 227 samples are LED negative, specificity are 99.6%, 97.0%, 97.0% respectively. There are significant difference between results of LED and the other two methods （ P〈0.001）.Detection time of ZN,FM,LED are 186.7s. 75.1s. 72.2s respectively, detection time is significantly different between ZN and LED , but not between FM and LED （P〈0.05） . LED was highly appreciated with technicians involved in this study. Conclusions LED yields advantage results comparing with classical systems, and is the most friendly method of the three. It has the implementation value.