Compartmental model

Population is divided into different compartments, such as different health or epidemiological states, to describe the mechanism of a dynamic epidemic. Compartmental models can be employed to estimate quantities such as basic Reproduction Number, prevalence, and incidence of a disease.

S-I-R-S model: The following Susceptible-Infectious-Recovered-Susceptible (SIRS) model can be used when the immunity conferred after disease is not permanent; a recovered individual becomes susceptible to infection again after a period of time.