基于脉冲微分方程的COVID-19境外输入型病例对我国疫情防控影响的分析

The impact of imported cases on the control of COVID-19 in China

我国针对新型冠状病毒肺炎(COVID-19)展开了联防联控工作,目前国内防疫形势已趋于明朗,但境外疫情处于上升阶段,"外防输入"成为我国下一阶段疫情防控的重点.本文通过对COVID-19传播动力学模型引入脉冲项来描述境外输入型病例对于我国目前疫情防控的影响.本文研究3种控制程度不同的入境防疫政策,数值模拟了输入型病例对于与韩国存在人口流动的我国各个省市疫情发展的影响及相应医疗资源需求.数值实验表明,对于输入型人口总量较少的地区,我国现有的防疫政策能够很好地控制疫情发展;对于来自疫区输入型人口较多的省市,边防口岸的有效筛查和必要隔离是防止由于输入型病例引起我国疫情二次暴发的重要手段.

To control the outbreak of COVID-19, the Chinese government has been carrying on a series of joint prevention and control measures. Current domestic situation shows an encouraging sign of improvement. However,the situation abroad is in a serious phase. Therefore, interdicting abroad inputs will be the key point at the next stage. In this paper, we establish a dynamical model incorporating with impulse to describe the transmission of SARS-CoV-2 and analyze the impact of overseas inputs on domestic prevention and control. Considering the imported cases from a typical neighboring country, we study the impacts of control measures under three different levels of control strategy. The simulations for the provinces with risk are given. The numerical experiments show that the current epidemic prevention policy can control the development of the epidemic well in the areas with less imported population;for the provinces with more imported population from the epidemic area, the effective screening and necessary isolation at immigration ports are crucial for preventing the further outbreak caused by imported cases.