Department of Population Medicine, Harvard Medical School/Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA.
Clin Infect Dis. 2021 Apr 26;72(8):1467-1474. doi: 10.1093/cid/ciaa1249.
Defining the duration of infectivity of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has major implications for public health and infection control practice in healthcare facilities. Early in the pandemic, most hospitals required 2 negative RT-PCR tests before discontinuing isolation in patients with Covid-19. Many patients, however, have persistently positive RT-PCR tests for weeks to months following clinical recovery, and multiple studies now indicate that these generally do not reflect replication-competent virus. SARS-CoV-2 appears to be most contagious around the time of symptom onset, and infectivity rapidly decreases thereafter to near-zero after about 10 days in mild-moderately ill patients and 15 days in severely-critically ill and immunocompromised patients. The longest interval associated with replication-competent virus thus far is 20 days from symptom onset. This review summarizes evidence-to-date on the duration of infectivity of SARS-CoV-2, and how this has informed evolving public health recommendations on when it is safe to discontinue isolation precautions.
确定严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的传染性持续时间对医疗机构中的公共卫生和感染控制实践具有重大意义。在大流行早期，大多数医院要求患有 Covid-19 的患者在停止隔离之前进行 2 次阴性 RT-PCR 检测。然而，许多患者在临床康复后数周到数月内持续进行 RT-PCR 检测呈阳性，多项研究表明这些通常不反映具有复制能力的病毒。SARS-CoV-2 似乎在症状出现时最具传染性，此后传染性迅速下降，大约在轻度至中度疾病患者中 10 天后和严重至危重病患者和免疫功能低下患者中 15 天后接近零。迄今为止与具有复制能力的病毒相关的最长间隔时间是从症状出现开始的 20 天。这篇综述总结了迄今为止关于 SARS-CoV-2 传染性持续时间的证据，以及这些证据如何为不断发展的关于何时安全停止隔离预防措施的公共卫生建议提供信息。
