Prevalence is sometimes defined as a proportion with total population size in the denominator. A particular instance of infection prevalence will depend on a type of infectious agent, a population, and a period of time. Actual measures of prevalence are based only on reported cases and usually specify a time interval and geographic location. Other constraints may include population demographics.

A quality that inheres in an organism population and is the number of organisms in the population infected with an infectious agent at a specified time.

Albert Goldfain

Lindsay Cowell

Alexander Diehl