From the, National Institute of Respiratory Diseases and the Environment (INERAM), Asunción, Paraguay.
Department of Respiratory Diseases, Radboud University Medical Centre - TB Expert Centre Dekkerswald, Nijmegen - Groesbeek, The Netherlands.
J Intern Med. 2021 Aug;290(2):386-391. doi: 10.1111/joim.13281.
To end the tuberculosis (TB) epidemic, efficient diagnostic tools are needed. In a previous calibration study, a portable 'point of care' electronic nose device (Aeonose ) proved to be a promising tool in a hospital setting. We evaluated this technology to detect TB in an indigenous population in Paraguay.
A total of 131 participants were enrolled. eNose results were compared with anamnesis, physical examinations, chest radiography and mycobacterial cultures in individuals with signs and symptoms compatible with TB. The eNose analysis was performed in two stages: first, the training with a combination of a previous study population plus 47 participants from the new cohort (total n = 153), and second, the 'blind prediction' of 84 participants.
21% of all participants (n = 131) showed symptoms and/or chest radiography abnormalities suspicious of TB. No sputum samples resulted culture positive for Mycobacterium tuberculosis complex. Only one patient had a positive smell print analysis. In the training model, the specificity was 92% (95% confidence interval (CI): 85%-96%) and the negative predictive value (NPV) was 95%. In the blind prediction model, the specificity and the NPV were 99% (95% CI: 93%-99%) and 100%, respectively. Although the sensitivity and positive predictive value of the eNose could not be assessed in this cohort due to the small sample size, no active TB cases were found during a one year of follow-up period.
The eNose showed promising specificity and negative predictive value and might therefore be developed as a rule-out test for TB in vulnerable populations.
为了终结结核病（TB）流行，我们需要有效的诊断工具。在之前的校准研究中，一种便携式“即时诊断”电子鼻设备（Aeonose）在医院环境中被证明是一种很有前途的工具。我们在巴拉圭的一个土著人群中评估了这项技术对结核病的检测效果。
共纳入 131 名参与者。在有结核病症状和/或胸部影像学异常的个体中，将电子鼻的结果与病史、体格检查、胸部 X 线摄影和分枝杆菌培养进行比较。电子鼻分析分两个阶段进行：首先，对前一个研究人群加上新队列中的 47 名参与者（总 n=153）的组合进行训练，其次对 84 名参与者进行“盲测”。
所有参与者（n=131）中有 21%表现出结核病的症状和/或胸部影像学异常。没有痰样本培养出结核分枝杆菌复合体阳性。只有一名患者的气味图谱分析呈阳性。在训练模型中，特异性为 92%（95%置信区间（CI）：85%-96%），阴性预测值（NPV）为 95%。在盲测模型中，特异性和 NPV 分别为 99%（95%CI：93%-99%）和 100%。由于样本量小，无法评估电子鼻在本队列中的敏感性和阳性预测值，但在一年的随访期间没有发现活动性结核病病例。
电子鼻具有良好的特异性和阴性预测值，因此可以作为脆弱人群结核病的排除性检测手段。
