Goel Sonu, Pandey Rahul, Kumar Mohit, Kankaria Ankita, Khaneja Rajiv
Department of Community Medicine and School of Public Health, PGIMER, Chandigarh, India.
Revised National Tuberculosis Control Program, Chandigarh, India.
Lung India. 2018 Jul-Aug;35(4):307-311. doi: 10.4103/lungindia.lungindia_475_17.
Light-emitting diode fluorescence microscopy (LED-FM) has been recommended by the WHO and the Government of India over the conventional bright-field microscopy using Ziehl-Neelsen (ZN) staining for the diagnosis of sputum smear-positive tuberculosis (TB) suspects.
The aim of this study was to assess the effectiveness of LED-FM in detecting TB cases.
This retrospective cohort study was carried out in December 2016 using secondary data of the years 2011-2012 from designated microscopy centers (DMCs) at Chandigarh, India.
Two peripheral DMCs where conventional ZN microscopy was used were taken as controls comparable to two peripheral DMCs which used LED-FM services in programmatic settings. The record of all suspected TB patients who underwent sputum smear examination pre- and post-LED-FM introduction was compared for measuring smear-positive cases, conformational grading, and time taken to read per slide examined. Chi-square was applied to access the statistical significance.
Out of total 8850 cases registered after the inception of LED-FM microscopy services, case detection rate was 13.3%, with significant decrease in case detection rate at tertiary level DMCs, there was significant increase in case detection rate at peripheral DMCs operating with LED-FM in contrast to ZN microscopy which was used previously. Scanty grade smear increased significantly by 9.0%. The time taken per slide examination decreased by 57.1% (from 7 min on an average to 3 min on an average) after LED-FM was used.
LED-FM is easy to use, takes lesser time to examine slides, and has longer self-life. It also eases laboatory technician's task in reporting scanty grade positives which use to be challenging previously. The results of this study provide enough evidences to scale up the installation process and usage of LED-FM at DMCs for TB diagnosis in Indian settings.
世界卫生组织和印度政府已推荐使用发光二极管荧光显微镜（LED - FM），而非采用萋 - 尼（ZN）染色的传统明视野显微镜，用于诊断痰涂片阳性肺结核（TB）疑似病例。
本研究旨在评估LED - FM在检测结核病病例方面的有效性。
这项回顾性队列研究于2016年12月开展，使用了印度昌迪加尔指定显微镜中心（DMCs）2011 - 2012年的二级数据。
选取两个使用传统ZN显微镜的外周DMCs作为对照组，与两个在项目环境中使用LED - FM服务的外周DMCs进行对比。比较所有疑似结核病患者在引入LED - FM前后进行痰涂片检查的记录，以测量涂片阳性病例、确诊分级以及每张检查玻片的阅片时间。应用卡方检验来确定统计学意义。
在引入LED - FM显微镜服务后登记的总共8850例病例中，病例检出率为13.3%，三级水平DMCs的病例检出率显著下降，与之形成对比的是，使用LED - FM的外周DMCs的病例检出率显著增加，而此前使用的是ZN显微镜。少量分级涂片显著增加了9.0%。使用LED - FM后，每张玻片检查时间减少了57.1%（从平均7分钟降至平均3分钟）。
LED - FM易于使用，检查玻片所需时间较少，且使用寿命更长。它还减轻了实验室技术人员报告少量分级阳性结果的任务，而这在以前颇具挑战性。本研究结果提供了充分证据，以扩大在印度环境下DMCs安装和使用LED - FM进行结核病诊断的进程。
