Institute for Maternal and Child Health IRCCS Burlo Garofolo, 34137, Trieste, Italy.
Division of Laboratory Medicine, University Hospital Giuliano Isontina (ASU GI), 34128, Trieste, Italy.
Braz J Microbiol. 2022 Sep;53(3):1271-1277. doi: 10.1007/s42770-022-00758-6. Epub 2022 Apr 21.
The number of SARS-CoV-2 detection tests requested to the laboratories has dramatically increased together with an urgent need to release reliable responses in a very short time. The two options taken into consideration and analyzed in the current study were the point-of-care test (POCT) based on the nucleic acid amplification test (NAAT) and the Antigen (Ag) rapid test. The POCT-NAAT-based assay was compared with a rapid antigen test of nasopharyngeal swab samples. If the specimen tested positive, it was followed by viral load quantification and by the functional assessment of the residual infectivity. When the initial cycle threshold (Ct) was below 20 (100%), and in the range of 20-25 (92%) and of 25-30 (88%), a great concordance between the POCT-NAAT and the Ag test was observed. Moreover, the positivity of the antigen test was well correlated to a successful infection in vitro (78%), with greater concordance when the initial Ct below 20 or above 35 (100%) and in the range 20-25 (83%). Our findings showed that most of the swabs which tested positive using the antigen test were able to infect the cells in vitro, suggesting that probably only these samples hold residual infectivity and therefore an increased risk of virus transmission at the moment of being tested.
随着对实验室进行的 SARS-CoV-2 检测数量的急剧增加，迫切需要在极短的时间内发布可靠的结果。在当前的研究中，考虑并分析了两种选择，即基于即时检测（POCT）的核酸扩增测试（NAAT）和抗原（Ag）快速检测。将基于 POCT-NAAT 的检测与鼻咽拭子样本的快速抗原检测进行了比较。如果标本检测呈阳性，则进行病毒载量定量检测和剩余传染性的功能评估。当初始循环阈值（Ct）低于 20（100%）、在 20-25（92%）和 25-30（88%）范围内时，POCT-NAAT 和 Ag 检测之间观察到高度一致性。此外，抗原检测的阳性结果与体外成功感染密切相关（78%），当初始 Ct 低于 20 或高于 35（100%）以及在 20-25 范围内时，一致性更高（83%）。我们的研究结果表明，使用抗原检测呈阳性的大多数拭子都能够在体外感染细胞，这表明可能只有这些样本具有残留的传染性，因此在检测时存在增加的病毒传播风险。
