Department of Global Health and Social Medicine, Harvard Medical School, Boston, USA.
Socios En Salud Sucursal (Partners In Health), Lima, Peru.
Sci Rep. 2020 Dec 17;10(1):22231. doi: 10.1038/s41598-020-79297-9.
Tuberculosis (TB) diagnosis relies on a sputum sample, which cannot be easily obtained from all symptomatic patients. Mycobacterium tuberculosis DNA can be detected from oral swabs, a noninvasive, safe alternative sample type; however, reported sensitivities have been variable and likely depend on sample collection, processing procedures and host characteristics. We analyzed three buccal swab samples from 123 adults with culture-confirmed TB in Lima, Peru. We compared the sensitivity and specificity of two sample collection devices (OmniSwab and EasiCollect FTA cards) and examined factors associated with detection. DNA was extracted with a commercially available kit and detected via real-time PCR IS6110 amplification. Overall sensitivity for buccal samples was 51% (95% Confidence Interval [CI] 42-60%). Specificity from a single sample among healthy controls was 96.7% (95% CI 83-99.9%). Positive sputum smear and cavitary disease, correlates of disease burden, were associated with detection via buccal swab. Although we observed higher sensitivities with the Omniswab samples, this appeared to be due primarily to differences in patient characteristics (e.g., cavitary disease). Overall, our findings support the potential for a buccal sample-based TB assay. Future work should focus on assay optimization and streamlining the assay workflow.
肺结核（TB）的诊断依赖于痰样本，但并非所有有症状的患者都能轻易获得。从口腔拭子中可以检测到结核分枝杆菌 DNA，这是一种非侵入性、安全的替代样本类型；然而，据报道，其敏感性各不相同，可能取决于样本采集、处理程序和宿主特征。我们分析了来自秘鲁利马 123 例经培养证实的 TB 成人的 3 个口腔拭子样本。我们比较了两种样本采集装置（OmniSwab 和 EasiCollect FTA 卡）的敏感性和特异性，并检查了与检测相关的因素。使用市售试剂盒提取 DNA，并通过实时 PCR IS6110 扩增进行检测。口腔样本的总敏感性为 51%（95%置信区间 [CI] 42-60%）。健康对照组中单个样本的特异性为 96.7%（95%CI 83-99.9%）。阳性痰涂片和空洞性疾病是疾病负担的相关因素，与口腔拭子检测相关。尽管我们观察到 Omniswab 样本的敏感性更高，但这主要是由于患者特征（例如空洞性疾病）的差异。总的来说，我们的研究结果支持基于口腔样本的 TB 检测方法的潜力。未来的工作应侧重于优化检测方法和简化检测工作流程。
