In epidemiology, an epidemic (frae Greek ἐπί epi "upon or abuin" an δῆμος demos "fowk") occurs when new cases o a certain disease, in a gien human population, an during a gien period, substantially exceed what is expectit based on recent experience.[1][2]


  1. Principles of Epidemiology, Third Edition (PDF). Atlanta, Georgia: Centers for Disease Control and Prevention. 2012.
  2. Green MS, Swartz T, Mayshar E, Lev B, Leventhal A, Slater PE, Shemer J (January 2002). "When is an epidemic an epidemic?" (PDF). Isr. Med. Assoc. J. 4 (1): 3–6. PMID 11802306. Archived frae the oreeginal (PDF) on 2012-07-24.CS1 maint: multiple names: authors leet (link)