本文建立了一类具有潜伏期和免疫期的双时滞SEIRS传染病模型,在脉冲免疫接种和垂直传染条件下,分析了其全局动力学行为.利用频闪映射,获得了无病周期解,给出了此周期解的全局吸引性,并获得了系统一致持续生存的条件.
In this paper,a SEIRS epidemic model with two delays of latent period and immune period is formulated,and the global dynamics behaviors of the model under impulsive vaccination and vertical transmission are analyzed.By use of the stroboscopic map,an 'infection-free' periodic solution is obtained,and the global attractivity of the 'infection-free' periodic solution is given.Furthermore,the sufficient condition for permanence of the system is obtained.