Nature ( IF 64.8 ) Pub Date : 2021-10-25 , DOI: 10.1038/s41586-021-04130-w Jessica T Davis 1 , Matteo Chinazzi 1 , Nicola Perra 1, 2 , Kunpeng Mu 1 , Ana Pastore Y Piontti 1 , Marco Ajelli 3 , Natalie E Dean 4 , Corrado Gioannini 5 , Maria Litvinova 3 , Stefano Merler 6 , Luca Rossi 5 , Kaiyuan Sun 7 , Xinyue Xiong 1 , Ira M Longini 8 , M Elizabeth Halloran 9, 10 , Cécile Viboud 7 , Alessandro Vespignani 1
Considerable uncertainty surrounds the timeline of introductions and onsets of local transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) globally1,2,3,4,5,6,7. Although a limited number of SARS-CoV-2 introductions were reported in January and February 2020 (refs.8,9), the narrowness of the initial testing criteria, combined with a slow growth in testing capacity and porous travel screening10, left many countries vulnerable to unmitigated, cryptic transmission. Here we use a global metapopulation epidemic model to provide a mechanistic understanding of the early dispersal of infections and the temporal windows of the introduction of SARS-CoV-2 and onset of local transmission in Europe and the USA. We find that community transmission of SARS-CoV-2 was likely to have been present in several areas of Europe and the USA by January 2020, and estimate that by early March, only 1 to 4 in 100 SARS-CoV-2 infections were detected by surveillance systems. The modelling results highlight international travel as the key driver of the introduction of SARS-CoV-2, with possible introductions and transmission events as early as December 2019 to January 2020. We find a heterogeneous geographic distribution of cumulative infection attack rates by 4 July 2020, ranging from 0.78% to 15.2% across US states and 0.19% to 13.2% in European countries. Our approach complements phylogenetic analyses and other surveillance approaches and provides insights that can be used to design innovative, model-driven surveillance systems that guide enhanced testing and response strategies.
中文翻译:
SARS-CoV-2 的隐秘传播和第一波 COVID-19
严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 在全球范围内的引入和本地传播的时间线存在相当大的不确定性1,2,3,4,5,6,7。尽管 2020 年 1 月和 2 月报告的 SARS-CoV-2 引入数量有限(参考文献8,9),但初始检测标准的狭窄,加上检测能力增长缓慢和旅行筛查的漏洞10,导致许多人容易遭受彻底、隐秘传播的国家。在这里,我们使用全球集合种群流行病模型来提供对感染早期扩散、SARS-CoV-2 引入的时间窗口以及欧洲和美国本地传播开始的机制理解。我们发现,到 2020 年 1 月,欧洲和美国的多个地区可能已经出现 SARS-CoV-2 的社区传播,并估计到 3 月初,仅检测到 100 例 SARS-CoV-2 感染中的 1 到 4 例通过监控系统。建模结果强调国际旅行是 SARS-CoV-2 引入的关键驱动因素,最早可能在 2019 年 12 月至 2020 年 1 月发生引入和传播事件。我们发现,截至 2020 年 7 月 4 日,累积感染攻击率存在异质地理分布美国各州的这一比例为 0.78% 至 15.2%,欧洲国家的比例为 0.19% 至 13.2%。我们的方法补充了系统发育分析和其他监测方法,并提供了可用于设计创新的、模型驱动的监测系统的见解,以指导增强的测试和应对策略。