Pediatric Emergency Unit, Department of Medical and Surgical Sciences, IRCCS Azienda Ospedaliero-Universitaria, Polyclinic of St.Orsola, University of Bologna, 40138 Bologna, Italy.
Specialty School of Pediatrics-Alma Mater Studiorum-University of Bologna, 40138 Bologna, Italy.
Viruses. 2021 Oct 14;13(10):2071. doi: 10.3390/v13102071.
The gold standard for diagnosis of SARS-CoV-2 infection has been nucleic acid amplification tests (NAAT). However, rapid antigen detection kits (Ag-RDTs), may offer advantages over NAAT in mass screening, generating results in minutes, both as laboratory-based test or point-of-care (POC) use for clinicians, at a lower cost. We assessed two different POC Ag-RDTs in mass screening versus NAAT for SARS-CoV-2 in a cohort of pediatric patients admitted to the Pediatric Emergency Unit of IRCCS-Polyclinic of Sant'Orsola, Bologna (from November 2020 to April 2021). All patients were screened with nasopharyngeal swabs for the detection of SARS-CoV-2-RNA and for antigen tests. Results were obtained from 1146 patients. The COVID-19 Ag FIA kit showed a baseline sensitivity of 53.8% (CI 35.4-71.4%), baseline specificity 99.7% (CI 98.4-100%) and overall accuracy of 80% (95% CI 0.68-0.91); the AFIAS COVID-19 Ag kit, baseline sensitivity of 86.4% (CI 75.0-93.9%), baseline specificity 98.3% (CI 97.1-99.1%) and overall accuracy of 95.3% (95% CI 0.92-0.99). In both tests, some samples showed very low viral load and negative Ag-RDT. This disagreement may reflect the positive inability of Ag-RDTs of detecting antigen in late phase of infection. Among all cases with positive molecular test and negative antigen test, none showed viral loads > 10 copies/mL. Finally, we found one false Ag-RDTs negative result (low cycle thresholds; 9 × 10 copies/mL). Our results suggest that both Ag-RDTs showed good performances in detection of high viral load samples, making it a feasible and effective tool for mass screening in actively infected children.
SARS-CoV-2 感染的金标准诊断方法一直是核酸扩增检测（NAAT）。然而，快速抗原检测试剂盒（Ag-RDT）在大规模筛查中可能优于 NAAT，可在几分钟内生成结果，既可作为实验室检测，也可作为临床医生的即时检测（POC），成本更低。我们评估了两种不同的 POC Ag-RDT 在 SARS-CoV-2 大规模筛查中的性能，将其与核酸扩增检测在意大利博洛尼亚圣奥尔索拉综合医院儿科急诊病房（2020 年 11 月至 2021 年 4 月）收治的儿科患者队列中进行比较。所有患者均采用鼻咽拭子进行 SARS-CoV-2-RNA 检测和抗原检测。共获得 1146 例患者的结果。COVID-19 Ag FIA 试剂盒的基础灵敏度为 53.8%（CI 35.4-71.4%），基础特异性为 99.7%（CI 98.4-100%），总准确率为 80%（95%CI 0.68-0.91）；AFIAS COVID-19 Ag 试剂盒的基础灵敏度为 86.4%（CI 75.0-93.9%），基础特异性为 98.3%（CI 97.1-99.1%），总准确率为 95.3%（95%CI 0.92-0.99）。在这两种检测中，一些样本的病毒载量非常低且呈阴性抗原检测结果。这种不一致可能反映了抗原检测在感染后期无法检测抗原的阳性能力。在所有分子检测阳性、抗原检测阴性的病例中，均未发现病毒载量>10 拷贝/ml。最后，我们发现了一个假阴性的抗原检测结果（低循环阈值；9×10 拷贝/ml）。我们的研究结果表明，两种抗原检测试剂盒在检测高病毒载量样本方面均表现良好，使其成为主动感染儿童大规模筛查的一种可行且有效的工具。
