  In this paper, we consider a reaction-diffusion-advection SIS epidemic model
with saturated incidence rate and linear source. We study the uniform bounds of
parabolic system and some asymptotic behavior of the basic reproduction number
$\mathcal{R}_0$, according to which the threshold-type dynamics are given.
Furthermore, we show the globally asymptotic stability of the endemic
equilibrium in a special case with a large saturated incidence rate. Meanwhile,
we investigate the effects of diffusion, advection, saturation and linear
source on the asymptotic profiles of the endemic equilibrium. Our study shows
that advection may induce the concentration phenomenon and the disease will be
eradicated with small dispersal rate of infected individuals. Moreover, our
results also reveal that the linear source can enhance persistence of
infectious disease and large saturation can help speed up the elimination of
disease.
