Steingart Karen R, Ng Vivienne, Henry Megan, Hopewell Philip C, Ramsay Andrew, Cunningham Jane, Urbanczik Richard, Perkins Mark D, Aziz Mohamed Abdel, Pai Madhukar
Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California, San Francisco, CA, USA.
Lancet Infect Dis. 2006 Oct;6(10):664-74. doi: 10.1016/S1473-3099(06)70602-8.
In low-income and middle-income countries, direct (unconcentrated) sputum smear microscopy is the primary method for diagnosing pulmonary tuberculosis. The method is fast, inexpensive, and specific for Mycobacterium tuberculosis in high incidence areas. The main limitations of direct microscopy are its relatively low sensitivity, especially in individuals co-infected with HIV, and variable quality of the test in programme conditions. Thus, there is a need to identify methods to improve the sensitivity of microscopy. Physical and chemical sputum processing methods, including centrifugation, sedimentation, and bleach, have been studied and found to show promise. We did a systematic review to assess the ability of different processing methods to improve the sensitivity of microscopy. By searching many sources, we identified 83 studies. Overall, by comparison with direct smears, the results suggested that centrifugation with any of several chemical methods (including bleach) is more sensitive, that overnight sedimentation preceded by chemical processing is more sensitive, and that specificity is similar. There were insufficient data to determine the value of sputum processing methods in patients with HIV infection. Operational studies are needed to determine whether the increased sensitivity provided by processing methods is sufficient to offset their increased cost, complexity, and potential biohazards, and to examine their feasibility.
在低收入和中等收入国家，直接（未浓缩）痰涂片显微镜检查是诊断肺结核的主要方法。该方法快速、廉价，且在高发病地区对结核分枝杆菌具有特异性。直接显微镜检查的主要局限性在于其灵敏度相对较低，尤其是在合并感染艾滋病毒的个体中，以及在项目条件下检测质量参差不齐。因此，需要确定提高显微镜检查灵敏度的方法。包括离心、沉淀和漂白在内的物理和化学痰处理方法已被研究并发现具有前景。我们进行了一项系统评价，以评估不同处理方法提高显微镜检查灵敏度的能力。通过检索多个来源，我们确定了83项研究。总体而言，与直接涂片相比，结果表明采用几种化学方法（包括漂白）中的任何一种进行离心更灵敏，化学处理后进行过夜沉淀更灵敏，且特异性相似。尚无足够数据确定痰处理方法在艾滋病毒感染患者中的价值。需要进行操作性研究，以确定处理方法提高的灵敏度是否足以抵消其增加的成本、复杂性和潜在生物危害，并检验其可行性。
