Continuous model of an epidemic (Q1117163)

The following mathematical model predicts the consequences of an epidemic by considering the characteristics of a disease and it effects on a population of a given size. An epidemic can be viewed as a simple growth and decay process. The population of infectives, those infected by and capable of spreading the disease, grows while the population of susceptibles, those unexposed to the disease, decreases in size. A third possible population category are the removals, those either immune, quarantined or deceased. The simplest model of an epidemic is that of pure infection in which there are no removals and no addition to the susceptibles. In the second model, a population of removals is included. Still a third model could be used to remove susceptibles through immunization.