Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY, USA.
Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA.
J Clin Virol. 2020 Jul;128:104428. doi: 10.1016/j.jcv.2020.104428. Epub 2020 May 13.
The SARS-CoV-2 pandemic has created an urgent and unprecedented need for rapid large-scale diagnostic testing to inform timely patient management. However, robust data are lacking on the relative performance of available rapid molecular tests across a full range of viral concentrations.
This study aimed to compare two recently-authorized rapid tests, Cepheid Xpert Xpress SARS-CoV-2 and Abbott ID Now SARS-CoV-2, to the Roche cobas SARS-CoV-2 assay for samples with low, medium, and high viral concentrations.
A total of 113 nasopharyngeal swabs from remnant patient samples were tested, including 88 positives spanning the full range of observed Ct values on the cobas assay.
Compared to cobas, the overall positive agreement was 73.9% with ID Now and 98.9% with Xpert. Negative agreement was 100% and 92.0% for ID Now and Xpert, respectively. Both ID Now and Xpert showed 100% positive agreement for medium and high viral concentrations (Ct value <30). However, for Ct values >30, positive agreement was 34.3% for ID Now and 97.1% for Xpert.
While Xpert showed high agreement with cobas across a wide range of viral concentrations, this study highlights an important limitation of ID Now for specimens collected in viral or universal transport media with low viral concentrations. Further studies are needed to evaluate the performance of ID Now for direct swabs.
SARS-CoV-2 大流行造成了对快速大规模诊断检测的紧急和前所未有的需求，以便及时进行患者管理。然而，关于各种病毒浓度下现有快速分子检测的相对性能，缺乏有力的数据。
本研究旨在比较两种最近获得授权的快速检测方法，即 Cepheid Xpert Xpress SARS-CoV-2 和 Abbott ID Now SARS-CoV-2，与 Roche cobas SARS-CoV-2 检测方法在低、中、高病毒浓度样本中的性能。
总共检测了 113 份鼻咽拭子残留患者样本，包括在 cobas 检测方法上观察到的 Ct 值全范围内的 88 个阳性样本。
与 cobas 相比，ID Now 的总阳性符合率为 73.9%，Xpert 的阳性符合率为 98.9%。ID Now 和 Xpert 的阴性符合率分别为 100%和 92.0%。ID Now 和 Xpert 在中、高病毒浓度（Ct 值<30）时均表现出 100%的阳性符合率。然而，对于 Ct 值>30 的样本，ID Now 的阳性符合率为 34.3%，而 Xpert 的阳性符合率为 97.1%。
虽然 Xpert 在广泛的病毒浓度范围内与 cobas 表现出高度一致，但本研究强调了 ID Now 在采集病毒或通用运输介质中低病毒浓度样本时的一个重要局限性。需要进一步研究来评估 ID Now 用于直接拭子的性能。
