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In this work, we are concerned with the mathematical modeling and analysis of Ebola virus disease dynamics. Firstly, we design and analyze a nonlinear ordinary differential equations model integrating both direct and indirect transmission pathways with density-independent treatment and a composite nonlinear incidence function. We begin the analysis by proving the global existence of a unique positive and bounded solution. Then we compute the basic reproduction number on which relies the global dynamics of the model. We precisely show the existence of a unique disease-free equilibrium and that of a unique endemic equilibrium, and prove their global stability under appropriate assumptions on the basic reproduction number. Moreover, we perform the global sensitivity analysis of the basic reproduction number to assess the variability in the model predictions. We find that the forecasts closely agree with the 2014 outbreaks of the disease in Liberia and Sierra Leone. Secondly, we enrich this first model by extending it to a partially degenerate reaction–diffusion system via the inclusion of Fickian diffusion for susceptible and non-hospitalized infectious individuals in order to understand the dynamics of the disease transmission in a spatially homogeneous environment. We prove the global stability of the disease-free equilibrium and the uniform persistence when the basic reproduction number lies below and above one, respectively. Finally, numerical simulations are performed to illustrate some theoretical results obtained. [ABSTRACT FROM AUTHOR]

In this paper, an avian–human influenza epidemic model with diffusion, nonlocal delay and spatial homogeneous environment is investigated. This model describes the transmission of avian influenza among poultry, humans and environment. The behavior of positive solutions to a reaction–diffusion system with homogeneous Neumann boundary conditions is investigated. By means of linearization method and spectral analysis the local asymptotical stability is established. The global asymptotical stability for the poultry sub-system is studied by spectral analysis and by using a Lyapunov functional. For the full system, the global stability of the disease-free equilibrium is studied using the comparison Theorem for parabolic equations. Our result shows that the disease-free equilibrium is globally asymptotically stable, whenever the contact rate for the susceptible poultry is small. This suggests that the best policy to prevent the occurrence of an epidemic is not only to exterminate the asymptomatic poultry but also to reduce the contact rate between susceptible humans and the poultry environment. Numerical simulations are presented to illustrate the main results. [ABSTRACT FROM AUTHOR]