Global stability of an epidemic model with nonlinear incidence rate and differential infectivity

This paper considers an <f>SI1I2R</f> epidemic model that incorporates two classes of infectious individuals with differential infectivity, and the incidence rate is nonlinear. The basic reproduction number <f>R0</f> is found. If <f>R0⩽1</f>, the disease-free equilibrium is globally asymptotically stable and the disease always dies out eventually. If <f>R0>1</f>, a unique endemic equilibrium is locally asymptotically stable for general assumption. For a special case the global stability of the endemic equilibrium is proved. [Copyright &y& Elsevier]