Institute of Clinical and Biomedical Sciences, University of Exeter, RILD building, Royal Devon and Exeter Hospital (Wonford), Barrack Road, Exeter, UK.
NIHR Exeter Clinical Research Facility, Royal Devon and Exeter NHS Foundation Trust, Royal Devon and Exeter Hospital, Barrack Road, Exeter, UK.
Int J Infect Dis. 2022 Mar;116:418-425. doi: 10.1016/j.ijid.2021.12.312. Epub 2021 Dec 7.
This study aimed to evaluate the associations between COVID-19 severity and active viral load, and to characterize the dynamics of active SARS-CoV-2 clearance in a series of archival samples taken from patients in the first wave of COVID-19 infection in the South West of the UK.
Subgenomic RNA (sgRNA) and E-gene genomic sequences were measured in a retrospective collection of PCR-confirmed SARS-CoV-2-positive samples from 176 individuals, and related to disease severity. Viral clearance dynamics were then assessed in relation to symptom onset and last positive test.
Whilst E-gene sgRNAs declined before E-gene genomic sequences, some individuals retained sgRNA positivity for up to 68 days. 13% of sgRNA-positive cases still exhibited clinically relevant levels of virus after 10 days, with no clinical features previously associated with prolonged viral clearance times.
Our results suggest that potentially active virus can sometimes persist beyond a 10-day period, and could pose a potential risk of onward transmission. Where this would pose a serious public health threat, additional mitigation strategies may be necessary to reduce the risk of secondary cases in vulnerable settings.
本研究旨在评估 COVID-19 严重程度与活病毒载量之间的关联，并描述在英国西南部 COVID-19 感染第一波期间从患者中采集的一系列存档样本中活 SARS-CoV-2 清除的动力学特征。
对来自 176 名经 PCR 确证的 SARS-CoV-2 阳性样本的回顾性采集进行亚基因组 RNA（sgRNA）和 E 基因基因组序列测量，并与疾病严重程度相关联。然后，根据症状发作和最后一次阳性检测来评估病毒清除动力学。
尽管 E 基因 sgRNA 在 E 基因基因组序列之前下降，但一些个体的 sgRNA 阳性持续时间长达 68 天。在 10 天后，仍有 13%的 sgRNA 阳性病例表现出有临床意义的病毒载量，且没有以前与延长病毒清除时间相关的临床特征。
我们的结果表明，潜在的活病毒有时可能会持续存在超过 10 天，这可能构成潜在的传播风险。如果这对公共卫生构成严重威胁，可能需要采取额外的缓解策略，以减少在脆弱环境中发生二次感染的风险。
