The effects of diseases on competing species.

In this paper we study the dynamics of two competing species when one of them is subject to a disease. In order to keep the model simple, we present it under the strong assumption that the disease cannot cross the species barrier. We answer several important questions about the long term behavior of the environment. In this situation, no population is necessarily wiped out. Also, not every individual of the infected species is bound to contract the disease. Finally, disease-induced persistent cycles for the populations are admissible.