发光二极管荧光显微镜在基层实验室诊断结核分枝杆菌的应用评价

Evaluation on the Application of Fluorescence Microscopy with Light Emitting Diodes in Detecting Mycobacterium Tuberculosis in Laboratories of Basic Level

目的评价发光二极管荧光显微镜(LED)在基层实验室诊断结核分枝杆菌的应用情况。方法收集中国卫生部-盖茨基金会结核病防治项目结核病新诊断工具可行性子项目(即发光二极管荧光显微镜应用评估项目)湖南省宁乡县项目点的相关数据,运用回顾性的研究对萋尔-尼尔逊(Z-N)和LED在痰涂片直接镜检结核分枝杆菌阳性检出能力、报告结果的差异及两种方法受痰标本性状的影响等方面进行分析。结果初诊病例通过不同的染色和镜检方法阅片,Z-N阳性检出率为21.38%(388/1 815),LED阳性检出率为22.42%(407/1 815),LED比Z-N提高1.05%(19/1 815);随访患者Z-N、LED及LED比Z-N提高的阳性检出率分别为2.62%(48/1 831)、3.66%(67/1 831)和1.04%(19/1 831);Z-N和LED在初诊病例和随访患者两部分人群检查结果差异有统计学意义(χ2=1 678.990、1 214.956,P<0.001);两种方法在阳性结果分级报告上差异有统计学意义,尤其表现在涂片结果以实际观察到细菌条数进行描述的和阳性等级为4+以上的痰涂片上,但两种镜检方法所评定的阳性分级报告结果一致性尚可(McNemar-Bowker检验,χ2=103.145,P<0.001,kappa=0.777);痰标本性状在一定程度上影响着Z-N和LED两种检查方法在初诊病例涂阳患者的发现,Pearsonχ2=56.707、57.549,P<0.001,但在随访患者中表现出的差异无统计学意义;初诊病例和随访患者留取痰标本的性状差异有统计学意义(Pearsonχ2=59.614,P<0.001)。结论 Z-N和LED两种检查方法一致性较好,且LED在一定程度上优于Z-N,在基层肺结核患者的发现和治疗检测上有一定的应用价值。

Objective To evaluate the application of fluorescence microscopy with light emitting diodes（LED） in detecting Mycobacterium tuberculosis in laboratories of basic level. Methods The relevant data of New TB Diagnostic Tools Feasibility Subproject（namely Fluorescence Microscopy with Light-emitting Diodes Application Assessment Project）,China Ministry of Health-the Gates Foundation Tuberculosis Control Project,were collected in the project point of Ningxiang county,Hunan province.The detection capabilities for Mycobacterium tuberculosis by Ziehl-Neelsen（Z-N） and LED,the differences in report results and the influences of the specimen nature were analyzed in primary tuberculosis laboratories by retrospective studies. Results The specimens of the patients were subject to different staining and microscopic examinations.For the specimens of the newly diagnosed cases,the positive rate by Z-N was 21.38%（388/1,815）,and that by LED was 22.42%（407/1,815）.For the specimens of the follow-up patients,the positive rates were 2.62%（48/1,831） for Z-N and 3.66%（67/1,831） for LED.The positive rates by Z-N and LED showed significant differences both for the newly diagnosed patients and the follow-up cases（χ2=1,678.990 and 1,214.956 respectively,both P0.001）.The grading results for positive specimens by the two methods were different,especially when the results of sputum smear were described as the number of Mycobacterium tuberculosis actually observed or were described as positive above 4＋ grade.But overall,LED had a fair consistency with Z-N in result reporting（χ2=103.145,P0.001,kappa=0.777,by McNemar-Bowker test）.The nature of the sputum specimens did to some extent influence the finding of new diagnosed cases by Z-N and LED（χ2=56.707 and 57.549 respectively,both P0.001）,but it was not the case for the follow-up patients.The nature of the sputum specimens from the newly diagnosed patients was significantly different from those from the follow-up ones（χ2=59.614,P0.001）.Conclusions LED has a fair consistency with Z-N,and to some extent,LED is superior to Z-N.LED has application value in the detection and treatment of patients with pulmonary tuberculosis in the clinics of basic level.