Spreading and vanishing in a West Nile virus model with expanding fronts

Abstract

Abstract. In this paper, we study a simplified version of a West Nile virus model discussed by Lewis et al. [28], which was considered as a first approximation for the spatial spread of WNv. The basic reproduction number R 0 for the non-spatial epidemic model is defined and a threshold parameter R D 0 for the corresponding problem with null Dirichlet boundary condition is introduced. We consider a free boundary problem with coupled system, which describes the diffusion of birds by a PDE and the movement of mosquitoes by a ODE. The risk index R F 0 (t) associated with the disease in spatial setting is represented. Sufficient conditions for the WNv to eradicate or to spread are given. The asymptotic behavior of the solution to system when the spreading occurs are considered. It is shown that the initial number of infected populations, the diffusion rate of birds and the length of initial habitat exhibit important impacts on the vanishing or spreading of the virus. Numerical simulations are presented to illustrate the analytical results.MSC: primary: 35R35; secondary: 35K60

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“…Nowadays it is widely recognized that spatial spread of an infection is closely related to the heterogeneity of the environment and the spatial-temporal movement of the hosts. This is well supported by numerous research on diseases including malaria [38,39], rabies [27,28,45], dengue fever [52], West Nile virus [34,53], hantavirus [1,2], Asian longhorned beetle [22,23], etc; see [51] and references therein. A popular way to incorporate spatial movement of hosts into epidemic models is to assume host random movements, leading to coupled reaction-diffusion equations.…”

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Coexistence of a cross-diffusive West Nile virus model in a heterogenous environment

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