Spreading Dynamics of an SEIR Model with Delay on Scale-Free Networks

In this paper, to be more precise in modeling the real epidemic spread, an SEIR model with delay describing the fixed latent period is studied on scale-free networks. The basic reproduction number, which serves as a critical threshold of epidemic spread, is calculated. The formula for the basic reproduction number shows that adding delay decreases the basic reproduction number. By constructing appropriate Lyapunov functions, the global stability of disease-free and endemic equilibria is investigated. Finally, numerical simulations are performed to illustrate the effect of network structures and model parameters on the basic reproduction numbers and disease spreading processes.