characteristic of inheres in quality infectious disease lifetime prevalence Alexander Diehl Lindsay Cowell Albert Goldfain A quality that inheres in an organism population and is the number of organisms in the population who have, at any point during their lives, been bearers of an infectious disease and experienced realization of the disease. Prevalence is sometimes defined as a proportion with total population size in the denominator. A particular instance of infectious disease lifetime prevalence will depend on a type of infectious disease and a population. Actual measures of prevalence are based only on reported cases and usually specify a geographic location. Other constraints may include population demographics. organism population