Evolution of virulence when transmission occurs before disease.

The article reports on the development of two models to help understand the evolution of the virulence of infectious diseases. The models of infection differ in virulence and transmission rate, to determine the evolutionary stable strategy (ESS) and compare the transition and rate of recovery. The virulence of the ESS decreases when transmission occurs at the late stage of the infection. The increase in ESS virulence and transition rate result in recovery from the disease.