Stability and Hopf bifurcation of a delayed virus infection model with latently infected cells and Beddington-DeAngelis incidence

In this paper,the dynamical behaviors for a five-dimensional virus infection model with Latently Infected Cells and Beddington-DeAngelis incidence are investigated.In the model,four delays which denote the latently infected delay,the intracel-lular delay,virus production period and CTL response delay are considered.We define the basic reproductive number and the CTL immune reproductive number.By using Lyapunov functionals,LaSalle's invariance principle and linearization method,the threshold conditions on the stability of each equilibrium are established.It is proved that when the basic reproductive number is less than or equal to unity,the infection-free equilibrium is globally asy mptot ically stable;when the CTL immune repro-ductive number is less than or equal to unity and the basic reproductive number is greater than unity,the immune free infection equilibrium is globally asymptotically stable;when the CTL immune reproductive number is greater than unity and immune response delay is equal to zero,the immune infection equilibrium is globally asymptotically stable.The results show that immune response delay may destabilize the steady state of infection and lead to Hopf bifurcation.The existence of the Hopf bifurcation is discussed by using immune response delay as a bifurcation parameter.Numerical simulations are carried out to justify the analytical results.