Stability analysis of delayed SIR epidemic models with a class of nonlinear incidence rates
Stability analysis of delayed SIR epidemic models with a class of nonlinear incidence rates
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DOI:
10.1016/j.amc.2011.11.016
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发表时间:
2012
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影响因子:
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通讯作者:
Yoichi Enatsu;E. Messina;Y. Muroya;Y. Nakata;E. Russo;A. Vecchio
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文献类型:
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作者:
Yoichi Enatsu;E. Messina;Y. Muroya;Y. Nakata;E. Russo;A. Vecchio
We analyze stability of equilibria for a delayed SIR epidemic model, in which population growth is subject to logistic growth in absence of disease, with a nonlinear incidence rate satisfying suitable monotonicity conditions. The model admits a unique endemic equilibrium if and only if the basic reproduction number R0exceeds one, while the trivial equilibrium and the disease-free equilibrium always exist. First we show that the disease-free equilibrium is globally asymptotically stable if and only if R0⩽1. Second we show that the model is permanent if and only if R0>1. Moreover, using a threshold parameter R¯0characterized by the nonlinear incidence function, we establish that the endemic equilibrium is locally asymptotically stable for 1<R0⩽R¯0and it loses stability as the length of the delay increases past a critical value for 1<R¯0<R0. Our result is an extension of the stability results in [J.-J. Wang, J.-Z. Zhang, Z. Jin, Analysis of an SIR model with bilinear incidence rate, Nonlinear Anal. RWA 11 (2009) 2390–2402].