Beijing Center for Disease Prevention and Control & Beijing Research Center for Preventive Medicine, Beijing, China.
University of New South Wales, Sydney, Australia.
J Epidemiol Community Health. 2021 Jan;75(1):84-87. doi: 10.1136/jech-2020-214635. Epub 2020 Aug 27.
The presymptomatic transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been documented in limited clusters, and it is predicted through modelling. However, there is a lack of evidence from observations with a large sample size.
We used data from meticulous contact tracing of people exposed to cases of SARS-CoV-2 to estimate the proportion of cases that result from the presymptomatic transmission of the virus in Beijing during January 2020 and February 2020.
The results showed that presymptomatic transmission occurred in at least 15% of 100 secondary COVID-19 cases. The earliest presymptomatic contact event occurred 5 days prior to the index case's onset of symptoms, and this occurred in two clusters.
The finding suggested that the contact tracing period should be earlier and highlighted the importance of preventing transmission opportunities well before the onset of symptoms.
有限的聚集性病例中已记录到严重急性呼吸综合征冠状病毒 2 型（SARS-CoV-2）的症状前传播，并且通过建模进行了预测。然而，缺乏大样本量观察的证据。
我们使用对接触 SARS-CoV-2 病例的人员进行的细致接触追踪数据，来估计 2020 年 1 月和 2 月北京 SARS-CoV-2 病毒症状前传播导致的病例比例。
结果表明，100 例继发 COVID-19 病例中至少有 15%是由病毒的症状前传播引起的。最早的症状前接触事件发生在指数病例出现症状前 5 天，这发生在两个聚集性病例中。
该研究结果表明，接触者追踪期应更早，突出了在出现症状之前预防传播机会的重要性。
