The Stability and the Permanence of an SIRS Epidemic Model with Healing Period and Immune Expiration Period.

An SIRS epidemic model with two time delays in healing period and immune expiration period is researched. The threshold conditions which determines the epidemic termination were found out, the free-equilibrium and endemic equilibrium were calculated, and the global stability of free-equilibrium was proved. Using the method of rebuttal evidence and the comparison principle of differential equations, the uniform persistence of disease is proved. Immune expiration period and the recover period for the influence of epidemic model by numerical simulation were analyzed at last. [ABSTRACT FROM AUTHOR]