Fig. 2.

Stability of E₂ in models A, B, and C. Parameters are k = 0.5, μ = 0.06, a_q = 0.15, k_m = 0.4, μ_d = 1, χ = 0, $\frac{1}{4}$ (lower and upper dashed blue lines, respectively) and β₁ and β₂ are independent (and related to R₁ and R₂). The stability region of E₂ is the area below the solid line (red) in the model without coinfection (model A) and below the curved dashed lines (blue) in model B, where the upper of these refers to the coinfection model with strain replacement (see Section 2.3). (Color figure online.)