Abstract
In this chapter, the compartmental models for disease transmission are described and analyzed. At the outset, models for epidemics are illustrated, showing how to calculate the basic reproduction number and the final size of the epidemic. The authors also study models with multiple compartments, including treatment or isolation of infectives. Subsequently, they consider models including births and deaths in which there may be an endemic equilibrium and study the asymptotic stability of equilibria. They conclude by studying the age of infection models which give a unifying framework for more complicated compartmental models.