背景:结核病是导致1的全球健康问题。每年有400万人死亡。据估计,痰涂片诊断阴性,但培养阳性的肺结核诊断占肺结核传播的12.6%。通过涂片显微镜涂片进行TB诊断的最低检测限(LOD)为每毫升痰中5,000至10,000个杆菌(CFU/ml),导致漏诊病例和假阳性。然而,GeneXpert技术,痰液样本的LOD为131-250CFU/ml,其实施被认为有助于早期发现结核病和耐药结核病病例。自2013年以来,加纳卫生服务(GHS)在加纳的所有地区医院引入了GeneXpertMTB/RIF诊断,然而,没有关于显微镜检查和GeneXpert结核病诊断跨医疗机构的性能评估的报道.该研究比较了2016年至2020年在开普海岸教学医院(CCTH)通过显微镜和XpertMTB进行常规结核病诊断的结果。
方法:该研究回顾性比较了2016年至2020年在开普海岸教学医院(CCTH)的常规显微镜和GeneXpert结核病诊断结果。简而言之,对于每一例疑似结核感染病例,将痰液标本收集到20mL无菌旋盖容器中,并在24小时内处理。使用NALC-NaOH方法对样品进行净化,最终NaOH浓度为1%。离心后弃去上清液,剩余的沉淀溶解在1-1.5ml磷酸盐缓冲液(PBS)中并用于诊断。固定涂片为Ziehl-Neelsen抗酸染色,在显微镜下观察,其余部分用于GeneXpertMTB/RIF诊断。使用GraphPadPrism分析数据。
结果:50.11%(48.48-51.38%)为女性,奇数比率(95%CI)为1.004(0.944-1.069),更有可能向结核病诊所报告可疑结核病诊断。第一次痰涂片阳性病例为6.6%(5.98-7.25%),第二痰为6.07%(5.45-6.73%)。XpertMTB-RIF诊断在第一个涂片阴性TB样品中检测到2.93%(10/341)(1.42-5.33%),在第二个涂片阴性TB样品中检测到5.44%(16/294)(3.14-8.69%)。XpertMTB-RIF在涂片阳性中的患病率显示,男性为56.87%(178/313)和56.15%(137/244),女性为43.13%(135/313)和43.85%(107/244)第一次和第二次痰。此外,涂片1的假阴性涂片为0.18%(10/5607),涂片2的假阴性涂片为0.31%(16/5126)。
结论:结论:与传统涂片镜检法相比,该研究强调了GeneXpert法检测MTB的灵敏度更高.GeneXpert测定从涂片1和涂片2样品中鉴定出10和16个阳性MTB,它们是显微镜阴性的。
BACKGROUND: Tuberculosis is a global health problem that causes 1. 4 million deaths every year. It has been estimated that sputum smear-negative diagnosis but culture-positive pulmonary TB diagnosis contribute to 12.6% of pulmonary TB transmission. TB diagnosis by smear
microscopy smear has a minimum detection limit (LOD) of 5,000 to 10,000 bacilli per milliliter (CFU/ml) of sputum result in missed cases and false positives. However, GeneXpert technology, with a LOD of 131-250 CFU/ml in sputum samples and its implementation is believe to facilitate early detection TB and drug-resistant TB case. Since 2013, Ghana health Service (GHS) introduce GeneXpert MTB/RIF diagnostic in all regional hospitals in Ghana, however no assessment of performance between
microscopy and GeneXpert TB diagnosis cross the health facilities has been reported. The study compared the results of routine diagnoses of TB by
microscopy and Xpert MTB from 2016 to 2020 at the Cape Coast Teaching Hospital (CCTH).
METHODS: The study compared routine microscopic and GeneXpert TB diagnosis results at the Cape Coast Teaching Hospital (CCTH) from 2016 to 2020 retrospectively. Briefly, sputum specimens were collected into 20 mL sterile screw-capped containers for each case of suspected TB infection and processed within 24 h. The samples were decontaminated using the NALC-NaOH method with the final NaOH concentration of 1%. The supernatants were discarded after the centrifuge and the remaining pellets dissolved in 1-1.5 ml of phosphate buffer saline (PBS) and used for diagnosis. A fixed smears were Ziehl-Neelsen acid-fast stain and observed under microscope and the remainings were used for GeneXpert MTB/RIF diagnosis. The data were analyze using GraphPad Prism.
RESULTS: 50.11% (48.48-51.38%) were females with an odd ratio (95% CI) of 1.004 (0.944-1.069) more likely to report to the TB clinic for suspected TB diagnosis. The smear-positive cases for the first sputum were 6.6% (5.98-7.25%), and the second sputum was 6.07% (5.45-6.73%). The Xpert MTB-RIF diagnosis detected 2.93% (10/341) (1.42-5.33%) in the first and 5.44% (16/294) (3.14-8.69%) in the second smear-negative TB samples. The prevalence of Xpert MTB-RIF across smear positive showed that males had 56.87% (178/313) and 56.15% (137/244) and females had 43.13% (135/313) and 43.85% (107/244) for the first and second sputum. Also, false negative smears were 0.18% (10/5607) for smear 1 and 0.31% (16/5126) for smear 2.
CONCLUSIONS: In conclusion, the study highlights the higher sensitivity of the GeneXpert assay compared to traditional smear
microscopy for detecting MTB. The GeneXpert assay identified 10 and 16 positive MTB from smear 1 and smear 2 samples which were microscopic negative.