Division of Medical Microbiology, UCT Lung Institute, University of Cape Town, Cape Town,, South Africa.
Eur Respir J. 2011 Dec;38(6):1393-7. doi: 10.1183/09031936.00023211. Epub 2011 Jun 9.
Light-emitting diode (LED) microscopy has recently been endorsed by the World Health Organization (WHO). However, it is unclear whether LED is as accurate and cost-effective as Ziehl-Neelsen (ZN) microscopy or mercury vapour fluorescence microscopy (MVFM) in tuberculosis (TB)-HIV-co-infected subjects. Direct and concentrated sputum smears from TB suspects were evaluated using combinations of LED microscopy, ZN microscopy and MVFM. Median reading time per slide was recorded and a cost analysis performed. Mycobacterial culture served as the reference standard. 647 sputum samples were obtained from 354 patients (88 (29.8%) were HIV-infected and 161 (26%) were culture-positive for Mycobacterium tuberculosis). Although overall sensitivity of LED compared with ZN microscopy or MVFM was similar, sensitivity of all three modalities was lower in HIV-infected patients. In the HIV-infected group, the sensitivity of LED microscopy was higher than ZN microscopy using samples that were not concentrated (46 versus 39%; p = 0.25), and better than MVFM using concentrated samples (56 versus 44; p = 0.5). A similar trend was seen in the CD4 count <200 cells · mL(-1) subgroup. Median (interquartile range) reading time was quicker with LED compared with ZN microscopy (1.8 (1.7-1.9) versus 2.5 (2.2-2.7) min; p ≤ 0.001). Average cost per slide read was less for LED microscopy (US$1.63) compared with ZN microscopy (US$2.10). Among HIV-TB-co-infected patients, LED microscopy was cheaper and performed as well as ZN microscopy or MVFM independent of the staining (ZN or auramine O) or processing methods used.
发光二极管（LED）显微镜最近得到了世界卫生组织（WHO）的认可。然而，在结核分枝杆菌（TB）-人类免疫缺陷病毒（HIV）合并感染的患者中，LED 显微镜是否与齐尔-尼尔森（ZN）显微镜或汞蒸气荧光显微镜（MVFM）一样准确且具有成本效益，目前尚不清楚。对 TB 疑似患者的直接浓缩痰液涂片进行了 LED 显微镜、ZN 显微镜和 MVFM 组合检查。记录了每张载玻片的平均阅读时间，并进行了成本分析。分枝杆菌培养作为参考标准。从 354 名患者中获得了 647 份痰样本（88 名（29.8%）HIV 感染，161 名（26%）分枝杆菌培养阳性）。虽然 LED 与 ZN 显微镜或 MVFM 相比，其总体敏感性相似，但所有三种方法在 HIV 感染者中的敏感性均较低。在 HIV 感染者中，未浓缩样本时 LED 显微镜的敏感性高于 ZN 显微镜（46%比 39%；p = 0.25），浓缩样本时优于 MVFM（56%比 44%；p = 0.5）。在 CD4 计数<200 个细胞·mL(-1)的亚组中也出现了类似的趋势。与 ZN 显微镜相比，LED 显微镜的平均（中位数（四分位距））阅读时间更快（1.8（1.7-1.9）比 2.5（2.2-2.7）分钟；p≤0.001）。与 ZN 显微镜相比，LED 显微镜每张载玻片的平均阅读成本较低（1.63 美元）。在 HIV-TB 合并感染的患者中，LED 显微镜的成本较低，与 ZN 显微镜或 MVFM 的性能相当，与使用的染色（ZN 或金胺 O）或处理方法无关。
