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Dynamics of disease spread in a predator-prey system

2014

Abstract

This paper discusses the dynamics of a communicable disease in a predator-prey system. It is assumed that a parasite is infectious and it spreads among preys according to a SIS (susceptible-infective-susceptible) model but not among predators, the predators stay healthy. Two predation response functions of Holling type II are used for both healthy and infected preys. The feasibility and stability conditions of the equilibrium points of the system are analyzed. The model has one trivial equilibrium and two free-disease positive equilibria; (i) in the absence of predator ( and (ii) in the presence of predator . The threshold condition of is derived. If it is below threshold, becomes stable and if above threshold, it is unstable. The basic reproduction numbers for and are 170 Asrul Sani et al. also derived, called dan , respectively. These basic numbers serve as thresholds. If or , the equlibrium point or becomes asymptotically locally stable. If or , the equilibrium or is unstable.