Use of light-emitting diode fluorescence microscopy to detect acid-fast bacilli in sputum
Use of light-emitting diode fluorescence microscopy to detect acid-fast bacilli in sputum
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DOI：
10.1086/589248
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发表时间：
2008-07-15
影响因子：
11.8
通讯作者：
Warren, Rob M.
中科院分区：
文献类型：
--
作者：
Marais, Ben J.;Brittle, Wendy;Warren, Rob M.
背景。与传统光学显微镜相比，荧光显微镜在评估结核病的痰涂片样本方面提供了众所周知的好处。然而，在资源有限的环境中，其使用受到激发光源高成本的限制。我们评估了荧光显微镜的诊断性能，使用新型发光二极管（LED）技术作为传统汞灯（MVP）的替代品。对到社区诊所就诊的疑似肺结核患者常规采集的痰标本进行auramine O染色，并使用2种不同的兴奋性光源（MVP和LED）进行评价；然后对这些标本进行Ziehl-Neelsen染色并使用光学显微镜重新检查。两名显微镜师独立评估所有涂片。细菌培养提供金标准。221份痰标本中，36份（16.3%）结核分枝杆菌培养阳性。不同方式的LED评估的敏感性和特异性分别为84.7%和98.9%；MVP评价分别为73.6%和99.8%；光镜下分别为61.1%和98.9%。LED评估的解读器变异kappa值为0.87，MVP评估的kappa值为0.79，光学显微镜的kappa值为0.77。荧光显微镜读取阴性涂片的平均时间为1.4 min，光镜为3.6 min，荧光显微镜可节省61%的时间。LED荧光显微镜提供了一个可靠的替代传统方法，并有许多有利的属性，促进改进，分散，诊断服务。
Background. Fluorescence microscopy offers well-described benefits, compared with conventional light microscopy, for the evaluation of sputum smear samples for tuberculosis. However, its use in resource-limited settings has been limited by the high cost of the excitatory light source. We evaluated the diagnostic performance of fluorescence microscopy, using novel light-emitting diode (LED) technology as an alternative to the conventional mercury vapor lamp (MVP).Methods. Routinely collected sputum specimens from persons suspected to have tuberculosis who attended community clinics were stained with auramine O and were evaluated using 2 different excitatory light sources (MVP and LED); these specimens were then Ziehl-Neelsen stained and reexamined using light microscopy. Two microscopists independently evaluated all smears. Bacterial culture provided the gold standard.Results. Of the 221 sputum specimens evaluated, 36 (16.3%) were positive for Mycobacterium tuberculosis by culture. Sensitivity and specificity documented for the different modalities were 84.7% and 98.9%, respectively, for the LED assessment; 73.6% and 99.8%, respectively, for the MVP assessment; and 61.1% and 98.9%, respectively, for light microscopy. kappa values for interreader variation were 0.87 for the LED assessment, 0.79 for the MVP assessment, and 0.77 for light microscopy. The mean time to read a negative smear was 1.4 min with fluorescence microscopy and 3.6 min with light microscopy, reflecting a time savings of 61% with fluorescence microscopy.Conclusion. LED fluorescence microscopy provides a reliable alternative to conventional methods and has many favorable attributes that facilitate improved, decentralized, diagnostic services.