Epidemiol Mikrobiol Imunol. 2021 Summer;70(3):156-160.
Antigen tests have emerged as an alternative to SARS-CoV-2 diagnostic PCR, thought to be valuable especially for the screening of bigger communities. To check appropriateness of the antigen based testing, we determined sensitivity of two point-of-care antigen tests when applied to a cohort of COVID-19 symptomatic, COVID-19 asymptomatic and healthy persons.
We examined nasopharyngeal swabs with antigen test 1 (Panbio Covid-19 Ag Rapid Test, Abbott) and antigen test 2 (Standard F Covid-19 Ag FIA, SD Biosensor). An additional nasopharyngeal and oropharyngeal swab of the same individual was checked with PCR (Allplex SARS-nCoV-2, Seegene). Within a 4-day period in October 2020, we collected specimens from 591 subjects. Of them, 290 had COVID-19 associated symptoms.
While PCR positivity was detected in 223 cases, antigen test 1 and antigen test 2 were found positive in 148 (sensitivity 0.664, 95%CI 0.599, 0.722) and 141 (sensitivity 0.623, 95%CI 0.558, 0.684) patients, respectively. When only symptomatic patients were analysed, sensitivity increased to 0.738 (95%CI 0.667, 0.799) for the antigen test 1 and to 0.685 (95%CI 0.611, 0.750) for the antigen test 2. The substantial drop in sensitivity to 12.9% (95%CI 0.067, 0.234) was observed for samples with the PCR threshold cycle above > 30.
Low sensitivity of antigen tests leads to the considerable risk of false negativity. It is advisable to implement repeated testing with high enough frequency if the antigen test is used as a frontline screening tool, and to follow with PCR if it is applied to vulnerable populations.
抗原检测已成为 SARS-CoV-2 诊断 PCR 的替代方法，被认为特别适用于更大社区的筛查。为了检查基于抗原的检测的适当性，我们确定了两种即时抗原检测在 COVID-19 症状患者、COVID-19 无症状患者和健康人群中的敏感性。
我们使用抗原检测 1（Panbio COVID-19 Ag 快速检测，雅培）和抗原检测 2（Standard F COVID-19 Ag FIA，SD 生物传感器）检测鼻咽拭子。同一个体的额外鼻咽和口咽拭子通过 PCR（Allplex SARS-nCoV-2，Seegene）进行检查。在 2020 年 10 月的 4 天内，我们收集了 591 名受试者的标本。其中，290 名有 COVID-19 相关症状。
PCR 阳性检测到 223 例，抗原检测 1 和抗原检测 2 在 148 例（敏感性 0.664，95%CI 0.599，0.722）和 141 例（敏感性 0.623，95%CI 0.558，0.684）患者中呈阳性。当仅分析有症状的患者时，抗原检测 1 的敏感性增加到 0.738（95%CI 0.667，0.799），抗原检测 2 的敏感性增加到 0.685（95%CI 0.611，0.750）。对于 PCR 阈值循环大于 30 的样本，敏感性显著下降至 12.9%（95%CI 0.067，0.234）。
抗原检测的低敏感性导致相当大的假阴性风险。如果抗原检测用作一线筛查工具，则建议以足够高的频率进行重复检测，并在应用于弱势群体时进行 PCR 检测。
