Department of Respiratory Sciences, University of Leicester, Leicester UK.
Department of Respiratory Sciences, University of Leicester, Leicester UK.
Lancet Infect Dis. 2020 May;20(5):607-617. doi: 10.1016/S1473-3099(19)30707-8. Epub 2020 Feb 19.
Tuberculosis remains a global health challenge, with early diagnosis key to its reduction. Face-mask sampling detects exhaled Mycobacterium tuberculosis. We aimed to investigate bacillary output from patients with pulmonary tuberculosis and to assess the potential of face-mask sampling as a diagnostic method in active case-finding.
We did a 24-h longitudinal study in patients from three hospitals in Pretoria, South Africa, with microbiologically confirmed pulmonary tuberculosis. Patients underwent 1 h of face-mask sampling eight times over a 24-h period, with contemporaneous sputum sampling. M tuberculosis was detected by quantitative PCR. We also did an active case-finding pilot study in inhabitants of an informal settlement near Pretoria. We enrolled individuals with symptoms of tuberculosis on the WHO screening questionnaire. Participants provided sputum and face-mask samples that were tested with the molecular assay Xpert MTB/RIF Ultra. Sputum-negative and face-mask-positive individuals were followed up prospectively for 20 weeks by bronchoscopy, PET-CT, and further sputum analysis to validate the diagnosis.
Between Sept 22, 2015, and Dec 3, 2015, 78 patients with pulmonary tuberculosis were screened for the longitudinal study, of whom 24 completed the study (20 had HIV co-infection). M tuberculosis was detected in 166 (86%) of 192 face-mask samples and 38 (21%) of 184 assessable sputum samples obtained over a 24-h period. Exhaled M tuberculosis output showed no diurnal pattern and did not associate with cough frequency, sputum bacillary content, or chest radiographic disease severity. On May 16, 2018, 45 individuals were screened for the prospective active case-finding pilot study, of whom 20 had tuberculosis symptoms and were willing to take part. Eight participants were diagnosed prospectively with pulmonary tuberculosis, of whom six were exclusively face-mask positive at screening. Four of these participants (three of whom were HIV-positive) had normal findings on chest radiography but had treatment-responsive early tuberculosis-compatible lesions on PET-CT scans, with Xpert-positive sputum samples after 6 weeks.
Face-mask sampling offers a highly efficient and non-invasive method for detecting exhaled M tuberculosis, informing the presence of active infection both with greater consistency and at an earlier disease stage than with sputum samples. The approach shows potential for diagnosis and screening, particularly in difficult-to-reach communities.
Wellcome Trust, CARA (Council for At-Risk Academics), University of Leicester, the UK Medical Research Council, and the National Institute for Health Research. VIDEO ABSTRACT.
结核病仍然是一个全球性的健康挑战，早期诊断是减少结核病的关键。口罩采样检测呼出的结核分枝杆菌。我们旨在研究肺结核患者的细菌产量，并评估口罩采样作为主动发现病例的诊断方法的潜力。
我们在南非比勒陀利亚的三家医院进行了一项为期 24 小时的纵向研究，纳入了经微生物学证实的肺结核患者。患者在 24 小时内进行了 8 次 1 小时的口罩采样，同时进行了同期的痰采样。采用定量 PCR 检测结核分枝杆菌。我们还在比勒陀利亚附近的一个非正规住区进行了一项主动发现病例的试点研究。我们招募了符合世界卫生组织筛查问卷中结核病症状的个体。参与者提供了痰液和口罩样本，这些样本通过分子检测 Xpert MTB/RIF Ultra 进行了检测。痰液阴性和口罩阳性的个体通过支气管镜检查、PET-CT 和进一步的痰分析进行前瞻性随访 20 周，以验证诊断。
2015 年 9 月 22 日至 12 月 3 日期间，对 78 例肺结核患者进行了纵向研究筛查，其中 24 例完成了研究（20 例合并 HIV 感染）。在 24 小时内获得的 192 个口罩样本和 38 个（21%）可评估痰样本中，检测到 166 个（86%）结核分枝杆菌。呼出的结核分枝杆菌量无昼夜模式，与咳嗽频率、痰中细菌含量或胸部 X 线疾病严重程度无关。2018 年 5 月 16 日，对 45 名个体进行了前瞻性主动发现病例的试点研究筛查，其中 20 名有结核病症状并愿意参加。20 名参与者被前瞻性诊断为肺结核，其中 8 名在筛查时仅表现为口罩阳性。在这 8 名参与者中（其中 6 名合并 HIV 感染），有 4 名（其中 3 名 HIV 阳性）在胸部 X 光检查中未见异常，但 PET-CT 扫描显示有早期与结核病相符的病变，有治疗反应，6 周后 Xpert 检测痰样本阳性。
口罩采样提供了一种高效、非侵入性的方法，可用于检测呼出的结核分枝杆菌，与痰样本相比，它更一致、更早地提示活动性感染的存在。该方法具有诊断和筛查的潜力，特别是在难以到达的社区。
惠康信托基金会、CARA（学术风险理事会）、莱斯特大学、英国医学研究理事会和英国国家健康研究所。
