resistant carriers

We consider the compartmental model for the non-immune disease with both ordinary and resistant carriers. The same infecting rate $\beta$ is assumed for both types of carriers, whereas the curing rates $\gamma$ and  $\gamma'$ for the ordinary and resistant carriers, respectively, are different. The conversion from an ordinary into resistant carrier takes place with the rate $\delta$. The stationary states for the model are evaluated and rewritten in a compact form using two reduced parameters that are combinations of initial four rates.