National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada.
Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Canada.
PLoS One. 2021 Dec 7;16(12):e0261003. doi: 10.1371/journal.pone.0261003. eCollection 2021.
The true severity of infection due to COVID-19 is under-represented because it is based on only those who are tested. Although nucleic acid amplifications tests (NAAT) are the gold standard for COVID-19 diagnostic testing, serological assays provide better population-level SARS-CoV-2 prevalence estimates. Implementing large sero-surveys present several logistical challenges within Canada due its unique geography including rural and remote communities. Dried blood spot (DBS) sampling is a practical solution but comparative performance data on SARS-CoV-2 serological tests using DBS is currently lacking. Here we present test performance data from a well-characterized SARS-CoV-2 DBS panel sent to laboratories across Canada representing 10 commercial and 2 in-house developed tests for SARS-CoV-2 antibodies. Three commercial assays identified all positive and negative DBS correctly corresponding to a sensitivity, specificity, positive predictive value, and negative predictive value of 100% (95% CI = 72.2, 100). Two in-house assays also performed equally well. In contrast, several commercial assays could not achieve a sensitivity greater than 40% or a negative predictive value greater than 60%. Our findings represent the foundation for future validation studies on DBS specimens that will play a central role in strengthening Canada's public health policy in response to COVID-19.
由于仅基于接受检测的人群，因此，COVID-19 感染的真实严重程度被低估了。虽然核酸扩增检测（NAAT）是 COVID-19 诊断检测的金标准，但血清学检测可提供更好的 SARS-CoV-2 流行率的人群水平估计。由于加拿大独特的地理位置（包括农村和偏远社区），在加拿大实施大型血清学调查存在许多后勤挑战。干血斑（DBS）采样是一种实用的解决方案，但目前缺乏使用 DBS 进行 SARS-CoV-2 血清学检测的比较性能数据。在这里，我们介绍了来自 SARS-CoV-2 DBS 面板的测试性能数据，该面板发送到加拿大各地的实验室，代表了针对 SARS-CoV-2 抗体的 10 种商业和 2 种内部开发的测试。三种商业检测均正确识别了所有阳性和阴性 DBS，其灵敏度、特异性、阳性预测值和阴性预测值均为 100%（95%CI=72.2，100）。两种内部开发的检测也同样表现良好。相比之下，几种商业检测的灵敏度均无法超过 40%，阴性预测值均无法超过 60%。我们的研究结果为未来的 DBS 标本验证研究奠定了基础，这将在加强加拿大针对 COVID-19 的公共卫生政策方面发挥核心作用。
