METHODS: This prospective longitudinal study at a large public university in Seattle, WA utilized remote enrollment, online surveys, and self-collected nasal swab specimens to evaluate Ag-RDT performance against real-time reverse transcription polymerase chain reaction (rRT-PCR) in the context of SARS-CoV-2 Omicron. Ag-RDT sensitivity and specificity within 1 day of rRT-PCR were evaluated by symptom status throughout the illness episode and Orf1b cycle threshold (Ct).
RESULTS: From February to December 2022, 5757 participants reported 17 572 Ag-RDT results and completed 12 674 rRT-PCR tests, of which 995 (7.9%) were rRT-PCR positive. Overall sensitivity and specificity were 53.0% (95% confidence interval [CI], 49.6%-56.4%) and 98.8% (95% CI, 98.5%-99.0%), respectively. Sensitivity was comparatively higher for Ag-RDTs used 1 day after rRT-PCR (69.0%), 4-7 days after symptom onset (70.1%), and Orf1b Ct ≤20 (82.7%). Serial Ag-RDT sensitivity increased with repeat testing ≥2 (68.5%) and ≥4 (75.8%) days after an initial Ag-RDT-negative result.
CONCLUSIONS: Ag-RDT performance varied by clinical characteristics and temporal testing patterns. Our findings support recommendations for serial testing following an initial Ag-RDT-negative result, especially among recently symptomatic persons or those at high risk for SARS-CoV-2 infection.
方法:这项在西雅图一所大型公立大学进行的前瞻性纵向研究,WA利用远程注册,在线调查,和自我收集的鼻拭子标本,以评估在SARS-CoV-2Omicron的背景下Ag-RDT对实时逆转录聚合酶链反应(rRT-PCR)的性能。通过整个疾病发作的症状状态和Orf1b周期阈值(Ct)评估rRT-PCR的1天内的Ag-RDT敏感性和特异性。
结果:从2022年2月至12月,5757名参与者报告了17572Ag-RDT结果,并完成了12674rRT-PCR测试,其中rRT-PCR阳性995例(7.9%)。总体敏感性和特异性为53.0%(95%置信区间[CI],49.6%-56.4%)和98.8%(95%CI,98.5%-99.0%),分别。rRT-PCR后1天使用Ag-RDT的敏感性相对较高(69.0%),症状发作后4-7天(70.1%),和Orf1bCt≤20(82.7%)。在初始Ag-RDT阴性结果后,重复测试≥2(68.5%)和≥4(75.8%)天,系列Ag-RDT敏感性增加。
结论:Ag-RDT表现因临床特征和时间检测模式而异。我们的发现支持在初始Ag-RDT阴性结果后进行系列测试的建议,特别是在最近有症状的人或SARS-CoV-2感染的高危人群中。