Global Dynamics of an Epidemic Model with a Ratio-Dependent Nonlinear Incidence Rate

Figure 2

Topological structure of system (3.1) at (𝑏/𝑑,0) when 𝑅₀=1, where 𝑏=1,𝑑=1,𝑘=1.5,𝛾=0.5,𝛼=1,𝜇=0.5.