Document Type : Research Paper
Authors
Department of Mathematics, Semnan University, P. O. Box 35195-363, Semnan, Iran
Abstract
In this paper, we model the spread of COVID-19 in a population of people travelling between two areas. New research implies that traveling of the asymptomatic infectious individuals, (i.e., infected individuals who have no symptoms of the disease and individuals with symptoms of the disease that are not detected by the healthcare system) can bring disease from one region to other regions even if the infectious individuals who are detected by the healthcare system, (i.e., confirmed cases), are inhibited from traveling among regions. We study the effect of travelling between two areas on the dynamics of COVID-19. Our model is formulated as a system of ordinary differential equations, with terms accounting for disease transmission, recovery, birth, death, and travel between two areas. We will give an explicit formula for calculating the basic reproduction number, $\mathcal{R}_{0}$, in the quarantine mode of two areas and explicit bounds on $\mathcal{R}_{0}$ for the case where the residents of both areas are in contact with each other. Our computations reveal the relationship between the basic reproduction number, a crucial quantity in epidemic control, and travel and return rates between areas. This suggests that it is essential to strengthen restrictions on passengers once infectious diseases appear.
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