Department of Infectious Diseases, University Hospitals of Leicester NHS Trust, Leicester, UK.
Department of Clinical Microbiology, University Hospitals of Leicester NHS Trust, Leicester, UK.
J Med Virol. 2021 Aug;93(8):5146-5151. doi: 10.1002/jmv.26860. Epub 2021 Feb 16.
Despite vaccination programs and antivirals, influenza remains a prominent cause of morbidity and mortality. The Xpert Xpress Flu/respiratory syncytial virus (RSV) test is a leading influenza point-of-care test, but its evaluation has been limited to nasopharyngeal samples. In addition, the clinical impacts of Xpress Flu/RSV have not yet been quantified. We evaluated the performance of Xpress Flu/RSV at three locations in a UK Hospital Trust against an existing laboratory assay. Multiple upper respiratory tract sample types were included. In addition, we calculated time saved by Xpert, and the associations between Xpert use and rates of early patient isolation and antiviral prescription as recorded at the time of the laboratory result being telephoned out. A total of 642 patients were included in the diagnostic performance analysis. There were 177 laboratory-confirmed cases of influenza A, 7 influenza B and 86 RSV. For influenza A, sensitivity and specificity were 96.6% (95% confidence interval [CI]: 92.8%-98.8%) and 98.1% (CI: 96.4%-99.1%), respectively. This was sustained across all locations and sample types. The negative predictive value was 98.7% (CI: 97.2%-99.4%). The median amount of time saved was 27.1 h. Xpert use was associated with sixfold higher rates of isolation and threefold higher rates of antiviral prescribing by the time the laboratory result was available. Sensitivity for RSV was lower at 86.0% (95% CI: 76.9%-92.6%). Xpert Xpress Flu/RSV reliably detects influenza A infection and has significant clinical impacts. Cartridge optimization is required to enable accurate multiplexing, including from a range of sample types.
尽管有疫苗接种计划和抗病毒药物，流感仍然是发病率和死亡率的主要原因。Xpert Xpress 流感/呼吸道合胞病毒 (RSV) 检测是一种领先的流感即时检测方法，但它的评估仅限于鼻咽样本。此外，Xpress Flu/RSV 的临床影响尚未量化。我们在英国一家医院信托的三个地点评估了 Xpress Flu/RSV 与现有实验室检测的性能。包括多种上呼吸道样本类型。此外，我们计算了 Xpert 节省的时间，以及 Xpert 使用与实验室结果电话通知时记录的早期患者隔离和抗病毒处方率之间的关联。共有 642 名患者纳入了诊断性能分析。有 177 例实验室确诊的甲型流感病例，7 例乙型流感和 86 例 RSV。对于甲型流感，灵敏度和特异性分别为 96.6%（95%置信区间 [CI]：92.8%-98.8%）和 98.1%（CI：96.4%-99.1%）。这在所有地点和样本类型中都得到了维持。阴性预测值为 98.7%（CI：97.2%-99.4%）。节省的中位数时间为 27.1 小时。Xpert 的使用与隔离率提高六倍和抗病毒处方率提高三倍有关，当实验室结果可用时。RSV 的灵敏度较低，为 86.0%（95% CI：76.9%-92.6%）。Xpert Xpress Flu/RSV 可靠地检测甲型流感感染，具有显著的临床影响。需要对试剂盒进行优化，以实现包括多种样本类型的准确多重检测。
