Department of Laboratory Medicine, Nagasaki University Hospital, 1-7-1, Sakamoto, Nagasaki, 852-8501, Japan.
Department of Microbiology, Graduate School of Medicine, Yamaguchi University, 1-1-1, Minami-Kogushi, Ube, 755-8505, Japan.
BMC Infect Dis. 2023 Nov 23;23(1):823. doi: 10.1186/s12879-023-08821-9.
A test-based strategy against coronavirus disease 2019 (COVID-19) is one of the measures to assess the need for isolation and prevention of infection. However, testing with high sensitivity methods, such as quantitative RT-PCR, leads to unnecessary isolation, whereas the lateral flow antigen test shows low sensitivity and false negative results. The purpose of this study was to evaluate the performance of the LumiraDx SARS-CoV-2 Ag test (Lumira Ag), a rapid microfluidic immunofluorescence method, in assessing infectivity.
This study was performed from March 2022 to July 2022. A pair of nasopharyngeal swab samples were obtained from each patient with mild COVID-19. One swab was used for Lumira Ag testing, and the other for quantitative RT-PCR testing and virus culture.
A total of 84 patients were included in the study. Among them, PCR, Lumira Ag test, and virus culture indicated positivity for 82, 66, and 24 patients, respectively. When comparing the Lumira Ag test to virus culture, its sensitivity was 100.0% (24/24), specificity, 30.0% (18/60); positive predictive value, 36.3% (24/66); and negative predictive value (NPV), 100.0% (18/18). The positive sample for virus culture was observed until the ninth day from the onset of symptoms, while the Lumira Ag test was observed until day 11.
The Lumira Ag test showed high sensitivity and NPV (100% each) compared to virus culture. A test-based strategy using the Lumira Ag test can effectively exclude COVID-19 infectiousness.
针对 2019 年冠状病毒病（COVID-19）的基于检测的策略是评估隔离和感染预防需求的措施之一。然而，使用高灵敏度方法（如定量 RT-PCR）进行检测会导致不必要的隔离，而侧向流动抗原检测则显示出低灵敏度和假阴性结果。本研究旨在评估 LumiraDx SARS-CoV-2 Ag 测试（Lumira Ag）的性能，这是一种快速的微流控免疫荧光法，用于评估传染性。
本研究于 2022 年 3 月至 2022 年 7 月进行。从每例轻度 COVID-19 患者中采集一对鼻咽拭子样本。一个拭子用于 Lumira Ag 检测，另一个用于定量 RT-PCR 检测和病毒培养。
共有 84 例患者纳入研究。其中，PCR、Lumira Ag 检测和病毒培养分别显示 82、66 和 24 例患者阳性。将 Lumira Ag 检测与病毒培养进行比较，其灵敏度为 100.0%（24/24），特异性为 30.0%（18/60）；阳性预测值为 36.3%（24/66）；阴性预测值（NPV）为 100.0%（18/18）。病毒培养的阳性样本一直观察到症状出现后的第 9 天，而 Lumira Ag 检测则观察到第 11 天。
与病毒培养相比，Lumira Ag 检测显示出高灵敏度和 NPV（均为 100%）。基于检测的策略使用 Lumira Ag 检测可以有效排除 COVID-19 的传染性。
