Fig 2.

Optimal particle decay rate minimizes endemic susceptible density. For solid line, μ = 0.5 and β = 10. S* reaches a local minimum at $\widehat{{\xi }_2}$, but S* minimized globally at ξ_min. Therefore, most competitive strain has minimal FLP decay rate. Dashed line shows effect of reducing host mortality rate μ to 0.05. S* is minimized globally at $\widehat{{\xi }_2},\text{where}1<\widehat{{\xi }_2}<10$. Dotted line shows effect of reducing FLP burst size to β = 1. S* is minimized globally at $\widehat{{\xi }_2}$. Other parameter values: α = 0.01, b_υ = 1, γ = 20, and σ = 3.