Department of Clinical Laboratory, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
Respirology. 2014 Jan;19(1):132-7. doi: 10.1111/resp.12192.
While commercial liquid culture techniques have emerged over 20 years ago, Ziehl-Neelsen (ZN) smear microscopy remains the primary method for diagnosis of tuberculosis (TB) in China because of cost considerations. The microscopic observation drug susceptibility (MODS) assay has been evaluated in different parts of the world to determine whether it can give comparable result to commercial liquid techniques. However, most reports detail evaluation of sputum specimens. This study evaluated the performance of MODS assay for detection of Mycobacterium tuberculosis in extrapulmonary specimens in a Chinese population.
A total of 173 samples, including pleural fluid (n = 112) and cerebrospinal fluid (CSF, n = 61) samples, were collected from patients suspected to have extrapulmonary TB and tested by ZN smear microscopy, Lowenstein-Jensen (LJ) culture and the MODS assay. Discordant results among MODS assay and the other two methods were resolved by 90-day follow-up evaluation for all suspected patients.
The sensitivity of the MODS assay on pleural fluid and CSF samples was 20.5% and 37.5%, respectively, while the specificity of MODS assay on both types of samples approximated 100%. The median time to culture results for the MODS and LJ methods was 14 days, 32 days for pleural fluid, and 9 days and 31 days for CSF samples, respectively.
MODS assay is useful to diagnose extrapulmonary TB and may be an effective and affordable method in resource-limited countries.
虽然商业液体培养技术已经出现了 20 多年，但由于成本考虑，齐尔-尼尔森（ZN）染色显微镜仍然是中国诊断结核病（TB）的主要方法。微观观察药物敏感性（MODS）检测法已经在世界不同地区进行了评估，以确定它是否能与商业液体技术得出可比的结果。然而，大多数报告详细说明了对痰标本的评估。本研究评估了 MODS 检测法在中国人群中对肺外标本中结核分枝杆菌的检测性能。
共收集了 173 份标本，包括胸腔积液（n=112）和脑脊液（CSF，n=61）标本，这些标本来自疑似患有肺外结核的患者，采用 ZN 染色显微镜、Lowenstein-Jensen（LJ）培养和 MODS 检测法进行检测。对所有疑似患者进行 90 天的随访评估，以解决 MODS 检测法与其他两种方法之间的不一致结果。
MODS 检测法对胸腔积液和 CSF 标本的敏感性分别为 20.5%和 37.5%，而 MODS 检测法对两种类型标本的特异性均接近 100%。MODS 检测法和 LJ 方法的培养结果中位数时间分别为胸腔积液 14 天，CSF 分别为 9 天和 31 天。
MODS 检测法对肺外结核的诊断是有用的，并且在资源有限的国家可能是一种有效和经济实惠的方法。
