Ping An Healthcare Technology, Beijing, China.
Tsinghua Clinical Research Institute (TCRI), School of Medicine, Tsinghua University, Beijing, China; Center for Global Health and Infectious Diseases, School of Medicine and Vanke School of Public Health, Tsinghua University, Beijing, China.
J Biomed Inform. 2021 Jun;118:103800. doi: 10.1016/j.jbi.2021.103800. Epub 2021 May 7.
As the potential spread of COVID-19 sparked by imported cases from overseas will pose continuous challenges, it is essential to estimate the effects of control measures on reducing the importation risk of COVID-19. Our objective is to provide a framework of methodology for quantifying the combined effects of entry restrictions and travel quarantine on managing the importation risk of COVID-19 and other pandemics by leveraging different sets of parameters.
Three major categories of control measures on controlling importation risk were parameterized and modelled by the framework: 1) entry restrictions, 2) travel quarantine, and 3) domestic containment measures. Integrating the parameterized intensity of control measures, a modified SEIR model was developed to simulate the case importation and local epidemic under different scenarios of global epidemic dynamics. A web-based tool was also provided to enable interactive visualization of epidemic simulation.
The simulated number of case importation and local spread modelled by the proposed framework of methods fitted well to the historical epidemic curve of China and Singapore. Based on the simulation results, the total numbers of infected cases when reducing 30% of visitor arrivals would be 88·4 (IQR 87·5-89·6) and 58·8 (IQR 58·3-59·5) times more than those when reducing 99% of visitor arrivals in mainland China and Singapore respectively, assuming actual time-varying R and travel quarantine policy. If the number of global daily new infections reached 100,000, 85%-91% of inbound travels should be reduced to keep the daily new infected number below 100 for a country with a similar travel volume as Singapore (daily 52,000 tourist arrivals in 2019). Whereas if the number was lower than 10,000, the daily new infected case would be less than 100 even with no entry restrictions.
We proposed a framework that first estimated the intensity of travel restrictions and local containment measures for countries since the first overseas imported case. Our approach then quantified the combined effects of entry restrictions and travel quarantine using a modified SEIR model to simulate the potential epidemic spread under hypothetical intensities of these control measures. We also developed a web-based system that enables interactive simulation, which could serve as a valuable tool for health system administrators to assess policy effects on managing the importation risk. By leveraging different sets of parameters, it could adapt to any specific country and specific type of epidemic.
This framework has provided a valuable tool to parameterize the intensity of control measures, simulate both the case importation and local epidemic, and quantify the combined effects of entry restrictions and travel quarantine on managing the importation risk.
由于海外输入病例引发的 COVID-19 潜在传播将持续带来挑战，因此有必要评估控制措施对降低 COVID-19 输入风险的效果。我们的目标是提供一种方法框架，通过利用不同参数集，量化入境限制和旅行检疫等控制措施对管理 COVID-19 和其他大流行病输入风险的综合影响。
通过该框架对控制输入风险的三大类控制措施进行参数化和建模：1）入境限制，2）旅行检疫，和 3）国内遏制措施。整合控制措施的参数化强度，开发了一个改良的 SEIR 模型，以模拟不同全球疫情动态情景下的病例输入和本地疫情。还提供了一个基于网络的工具，以实现疫情模拟的交互式可视化。
所提出的方法框架模拟的病例输入和本地传播数量与中国和新加坡的历史疫情曲线拟合良好。基于模拟结果，当将游客入境人数减少 30%时，中国大陆和新加坡的感染总人数将分别比减少 99%时多出 88.4（IQR 87.5-89.6）和 58.8（IQR 58.3-59.5）倍，假设实际的时变 R 和旅行检疫政策。如果全球每日新增感染人数达到 10 万，那么对于一个旅行量与新加坡类似的国家（2019 年每天有 52000 名游客入境），应减少 85%-91%的入境旅行，以将每日新增感染人数控制在 100 以下。而如果每日新增感染人数低于 10000，则即使没有入境限制，每日新增感染人数也将少于 100。
我们提出了一个框架，首先根据首例海外输入病例以来的情况，估计各国的旅行限制和本地遏制措施的强度。然后，我们使用改良的 SEIR 模型来量化入境限制和旅行检疫的综合效果，以模拟这些控制措施的假设强度下的潜在疫情传播。我们还开发了一个基于网络的系统，支持交互式模拟，这可以作为卫生系统管理者评估管理输入风险的政策效果的有价值工具。通过利用不同的参数集，它可以适应任何特定国家和特定类型的疫情。
该框架提供了一个有价值的工具，用于参数化控制措施的强度，模拟病例输入和本地疫情，并量化入境限制和旅行检疫对管理输入风险的综合影响。
