The COVID-19, which belongs to the family of Coronaviridae and is large-scale outbreak in the whole world, is a public health emergency for human beings and brings some very harmful consequences in social and economic fields. In order to modelling the COVID-19 and develop the efficient control method corresponding to the contacting distance, this paper proposes an SEIR-type epidemic model with the contacting distance between the healthy individuals and the asymptomatic or symptomatic infected individuals, and the immigration rate of the healthy individuals, since the contacting distance and the immigration rate are two critical factors which determine the transmission of the COVID-19. Firstly, the threshold contacting distance and the threshold immigration rate are obtained by analyze the dynamical behaviors of the proposed SEIR-type epidemic model in order to control the COVID-19. The effect of the contacting distance and the immigration rate on the control of the COVID-19 are revealed based on ecological and epidemiological issues. The results show that the COVID-19 will be controlled while the contacting distance between the healthy individuals and the symptomatic infected individuals is larger than the threshold value A~ and the immigration rate is smaller than the threshold value ~ d. Secondly, the sensitivity analysis is conducted and the results show that the contacting distance and the immigration rate play an important role in controlling the COVID-19. Finally, the numerical test for Wuhan city are conducted and the conclusions show that the extinct lag decreases as the the contacting distance increase or the immigration rate decrease. Our study could give some reasonable suggestions for the health officials and the public.
Modelling for The COVID-19 with The Contacting Distance