Analysis of a Dengue Disease Model with Nonlinear Incidence

Figure 4

Phase plot of 𝐼 verses 𝑆 showing stability of unique feasible endemic equilibrium point and instablity of disease free equilibrium point when 𝛿<1,  𝑅₀>1 for the parameter values 𝑏₁=10,  𝜆₁=0.0005,  𝛼=0.01,  𝜇₁=0.01,  𝛾=0.01,  𝜆₂=0.0003,  𝑏₂=60,  𝜇₂=0.5.