COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Arkansas Department of Health, Little Rock, Arkansas, USA.
Clin Infect Dis. 2021 Jul 15;73(Suppl 1):S58-S64. doi: 10.1093/cid/ciab310.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing remains essential for early identification and clinical management of cases. We compared the diagnostic performance of 3 specimen types for characterizing SARS-CoV-2 in infected nursing home residents.
A convenience sample of 17 residents were enrolled within 15 days of first positive SARS-CoV-2 result by real-time reverse transcription polymerase chain reaction (RT-PCR) and prospectively followed for 42 days. Anterior nasal swabs (AN), oropharyngeal swabs (OP), and saliva specimens (SA) were collected on the day of enrollment, every 3 days for the first 21 days, and then weekly for 21 days. Specimens were tested for presence of SARS-CoV-2 RNA using RT-PCR and replication-competent virus by viral culture.
Comparing the 3 specimen types collected from each participant at each time point, the concordance of paired RT-PCR results ranged from 80% to 88%. After the first positive result, SA and OP were RT-PCR-positive for ≤48 days; AN were RT-PCR-positive for ≤33 days. AN had the highest percentage of RT-PCR-positive results (21/26 [81%]) when collected ≤10 days of participants' first positive result. Eleven specimens were positive by viral culture: 9 AN collected ≤19 days following first positive result and 2 OP collected ≤5 days following first positive result.
AN, OP, and SA were effective methods for repeated testing in this population. More AN than OP were positive by viral culture. SA and OP remained RT-PCR-positive longer than AN, which could lead to unnecessary interventions if RT-PCR detection occurred after viral shedding has likely ceased.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）检测对于早期识别和临床管理病例仍然至关重要。我们比较了 3 种标本类型在感染疗养院居民中鉴定 SARS-CoV-2 的诊断性能。
在实时逆转录聚合酶链反应（RT-PCR）首次检测到 SARS-CoV-2 阳性结果后的 15 天内，对 17 名居民进行了便利抽样，并前瞻性随访了 42 天。在入组当天、前 21 天每 3 天以及随后的 21 天内每周采集前鼻拭子（AN）、咽拭子（OP）和唾液标本（SA）。使用 RT-PCR 检测标本中 SARS-CoV-2 RNA 的存在，并用病毒培养检测有复制能力的病毒。
比较每个参与者在每个时间点采集的 3 种标本类型，配对 RT-PCR 结果的一致性为 80%至 88%。在首次阳性结果后，SA 和 OP 的 RT-PCR 阳性结果持续时间≤48 天；AN 的 RT-PCR 阳性结果持续时间≤33 天。在参与者首次阳性结果≤10 天采集的 21 份 AN 中，RT-PCR 阳性结果的百分比最高（21/26 [81%]）。11 份标本通过病毒培养呈阳性：9 份 AN 是在首次阳性结果后≤19 天采集的，2 份 OP 是在首次阳性结果后≤5 天采集的。
AN、OP 和 SA 是该人群重复检测的有效方法。通过病毒培养，AN 比 OP 阳性的更多。SA 和 OP 的 RT-PCR 阳性持续时间长于 AN，如果 RT-PCR 检测发生在病毒脱落可能已经停止后，可能会导致不必要的干预。
