title: Farr's law applied to AIDS projections.
abstract: Farr's Law of Epidemics, first promulgated in 1840 and resurrected by Brownlee in the early 1900s, states that epidemics tend to rise and fall in a roughly symmetrical pattern that can be approximated by a normal bell-shaped curve. We applied this simple law to the reported annual incidence of cases of acquired immunodeficiency syndrome in the United States from 1982 through 1987. The 6 years of incidence data closely fit a normal distribution that crests in late 1988 and then declines to a low point by the mid-1990s. The projected size of the epidemic falls in the range of 200 000 cases. A continuing incidence of endemic cases can be expected to emerge, but we believe it will occur at a low level.
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles 90033.
authors.forename: D J
authors.initials: DJ
authors.lastname: Bregman
authors.forename: A D
authors.initials: AD
authors.lastname: Langmuir
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology*; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D006716:Homosexuality / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D015819:Substance Abuse, Intravenous / Q000453:epidemiology; D014481:United States / Q000453:epidemiology