mass action principle

mass action principle

a basic tenet of epidemiology, which relates the incidence of an epidemic disease in a given population to the number of current cases, the number of susceptible people, and the infection transmission parameter.

mass ac·tion prin·ci·ple

(mas ak'shŭn prin'si-pĕl) The fundamental principle in epidemic theory: the incidence of an infectious disease is determined by the product of the current prevalence and the number of susceptibles in the population.
See also: serial interval, infection transmission parameter