J Austral Math Soc Ser B 34 pp26--34, 1992.
(Received 19 September 1990; revised 18 February 1991)
In this paper, we study the asymptotic behavior of an SIRS epidemic model with a time delay in the recovered class and a nonlinear incidence rate. A conjecture of Hethcote et al. [5] on the global stability of the disease-free equilibrium is solved. Moreover, we analyse the model when the contact number takes its threshold value. We show that solutions tend to either the disease-free equilibrium or to a unique positive endemic equilibrium, and there is no periodic solution.
Last Modified: Mon Jan 7 16:35:23 2002