An SIR vector disease model with incubation time is studied under the assumption that the
susceptible of host population satisfies the logistic equation and the incidence rate is the
simple mass action incidence. Threshold quantity ℜ0 is derived which determines whether
the disease dies out or remains endemic. If ℜ0< 1, the disease-free equilibrium is globally
asymptotically stable and the disease eventually disappears. If ℜ0> 1, there will be an
endemic and the disease is permanent if it initially exists. Using the time delay (ie …