The calculation of the endemic threshold involves mathematical models and epidemiological data. A common model used is the SIR model (Susceptible-Infectious-Recovered), which helps in understanding the dynamics of disease spread. The basic reproduction number, or R0, is pivotal in these calculations. If the R0 is less than 1, the disease will eventually die out; if it is greater than 1, the disease will spread unless controlled by immunity or other factors.
