Epidemic vs. Pandemic

Epidemic and pandemic are used to describe widespread outbreaks of a disease, but there are subtle differences between the two words.

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Definition An epidemic occurs when the incidence rate (i.e. new cases in a given human population, during a given period) of a certain disease substantially exceeds what is "expected," based on recent experience. A pandemic is an epidemic of an infectious disease that spreads through human populations across a large region, like a continent.
Comparison Disease outbreak that is concentrated in a particular region. Disease outbreak that occurs over a wide geographic area and affects a very high proportion of the population.

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An epidemic (from Greek epi- upon + demos people) is a classification of a disease that appears as new cases in a given human population, during a given period, at a rate that substantially exceeds what is "expected," based on recent experience (the number of new cases in the population during a specified period of time is called the "incidence rate").

A pandemic (from Greek πᾶν (pan, “all”) + + δῆμος (dēmos, “the people”) is an epidemic that spreads across a large region (for example a continent), or even worldwide.

edit Differences Between an Epidemic and a Pandemic

Simply put, when an epidemic gets out of hand, it is called a pandemic. This has 2 nuances:

edit Video Explaining the Differences

In this video, Dr. Kenneth Alexander, chief of pediatric infectious diseases at the University of Chicago Medical Center, explains the differences between an outbreak, an epidemic, and a pandemic, and answers questions about the swine flu outbreak.

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Comments: Epidemic vs Pandemic

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Anonymous comments (5)

March 22, 2012, 5:13pm

hmmmm....."word shift", as you put it, does sometimes occur but not in all cases you've mentioned. Tsunami has always been the correct term in that "tidal" has been somewhat of a misnomer since tsunamis have nothing to do with tides. Pandemic has always been a valid term since it describes the severity of epidemic. All pandemics are epidemics but not all epidemics are pandemics.

— 128.✗.✗.7

April 28, 2009, 3:07am

Go back and read the definition. It says, "Simply put, when an epidemic gets out of hand, it is called a pandemic." Is it possible that no one is really trying to scare you but merely reassess the data using that (above) definition?

— 75.✗.✗.35

April 24, 2009, 9:48pm

I defy anyone to find a reference to the Spanish Flu Epidemic of 1919 as a Pandemic, before the mid-1990's. Research it. It was always called Epidemic before 1995, Pandemic afterwards. Look at the references too. Those before 1995 always used the word "epidemic" and no other word. I don't think the epidemic of 1919 got worse after 1995. Word inflation did. What I'm expecting the verbal inflaters to do is go back and try to wipe out or change the old references to epidemic. That word is simply not scary enough. Pandemic is, at least for now.

— 206.✗.✗.31

March 12, 2011, 1:22pm

This is a prime example of what I refer to as a wordshift. This happens frequently in our trendy and restless contemporary society. There is really very little actual difference in the conditions the two words describe.
It is merely change solely for the sake of change. "X" has always been called such and such and that's just plain boring so let's find a new word for it. Thus a swamp is now a 'wetland'; a jungle is now a 'rain forest'; a tidal wave a 'trunami'; a liberal is now a 'progressive'; and yes, a pain old epidemic is now a 'pandemic'. But someone try to find a 'pandemiologist'.

— 98.✗.✗.91

November 29, 2009, 2:43pm

America's Forgotten Pandemic: The Influenza of 1918,
o Author: Alfred Crosby
o Publisher: Cambridge: Cambridge University Press, 1989
o ISBN: 0521833949

— 174.✗.✗.70


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