Estimation of reproduction numbers of COVID-19 in typical countries and epidemic trends under different prevention and control scenarios
Estimation of reproduction numbers of COVID-19 in typical countries and epidemic trends under different prevention and control scenarios
复制标题
典型国家COVID-19繁殖数及不同防控场景下疫情趋势估算
DOI：
10.1007/s11684-020-0787-4
复制
发表时间：
2020-05-28
影响因子：
8.1
通讯作者：
Cai, Yong
中科院分区：
文献类型：
--
作者：
Xu, Chen;Dong, Yinqiao;Cai, Yong
2019冠状病毒病（COVID-19）已成为威胁生命的大流行病。不同国家的流行趋势因决策和资源调动的不同而有很大差异。我们分别使用最大似然法和序贯贝叶斯法计算了COVID-19的基本繁殖数（R 0）和有效繁殖数（Rt）的时变估计。欧洲和北美国家具有较高的R 0和不稳定的Rt波动，而一些受影响严重的亚洲国家表现出相对较低的R 0和下降Rtnow。非洲和拉丁美洲的患者数量仍然较低，但爆发大规模疫情的潜在风险不容忽视。然后模拟了三种情景，通过使用SEIR（易感，暴露，传染和移除）模型产生不同的结果。第一，基于证据的迅速反应产生较低的传播率，其次是降低RT。第二，在相对较晚的阶段实施有效的控制政策，尽管在早期阶段的巨大伤亡，仍然可以实现遏制和缓解。第三，明智地利用非洲和拉丁美洲发展中国家采取适当措施的时间窗口，可以挽救更多人的生命。我们的数学模型为国际社会制定合理的COVID-19遏制和缓解政策提供了证据。
The coronavirus disease 2019 (COVID-19) has become a life-threatening pandemic. The epidemic trends in different countries vary considerably due to different policy-making and resources mobilization. We calculated basic reproduction number (R0) and the time-varying estimate of the effective reproductive number (Rt) of COVID-19 by using the maximum likelihood method and the sequential Bayesian method, respectively. European and North American countries possessed higher R0and unsteady Rtfluctuations, whereas some heavily affected Asian countries showed relatively low R0and declining Rtnow. The numbers of patients in Africa and Latin America are still low, but the potential risk of huge outbreaks cannot be ignored. Three scenarios were then simulated, generating distinct outcomes by using SEIR (susceptible, exposed, infectious, and removed) model. First, evidence-based prompt responses yield lower transmission rate followed by decreasing Rt. Second, implementation of effective control policies at a relatively late stage, in spite of huge casualties at early phase, can still achieve containment and mitigation. Third, wisely taking advantage of the time-window for developing countries in Africa and Latin America to adopt adequate measures can save more people’s life. Our mathematical modeling provides evidence for international communities to develop sound design of containment and mitigation policies for COVID-19.