Table of ContentsView AllTable of ContentsEpidemic vs. PandemicMisuse of ‘Epidemic’Event ClassificationOther DefinitionsNotable Pandemics
Table of ContentsView All
View All
Table of Contents
Epidemic vs. Pandemic
Misuse of ‘Epidemic’
Event Classification
Other Definitions
Notable Pandemics
“Epidemic” and “pandemic” are two words that describe the spread of disease. “Epidemic” is used to describe a disease that has grown out of control and is activelyspreading. “Pandemic” is used to describe a disease that affects a whole country or the entire world.
Understanding the difference between an epidemic and a pandemic is helpful when considering public health news. Terms like these are meant to help the public respond to a health crisis so they can better control and prevent disease.
Learn more about the difference between the terms “epidemic” vs. “pandemic,“as well as other terms used to classify the spread of diseases.
Verywell / JR Bee
Medical professionals use the terms “epidemic” and “pandemic” to distinguish between the size and scale of a disease’s spread. When there is an “epidemic,” it generally refers to a sudden increase in the number of cases of a disease above what is normally expected.
For example, from 2014 to 2016, Ebola was considered an epidemic because the disease was spreading rapidly throughout parts of West Africa but did not spread throughout other parts of the world.
A pandemic, however, refers to an epidemic that has spread over several countries or continents, usually affecting a large number of people.COVID-19 is a pandemic because millions of cases have occurred all over the world.
What Is “Endemic”?“Epidemic” is sometimes confused with “endemic,” but the two words have different meanings. While “epidemic” describes how far a specific outbreak of a disease has spread, the word"endemic” refers to the constant presence of a disease in a geographic population.For example, chicken pox is considered endemic in the United States because it affects American school children at predictable rates.
What Is “Endemic”?
“Epidemic” is sometimes confused with “endemic,” but the two words have different meanings. While “epidemic” describes how far a specific outbreak of a disease has spread, the word"endemic” refers to the constant presence of a disease in a geographic population.For example, chicken pox is considered endemic in the United States because it affects American school children at predictable rates.
“Epidemic” is sometimes confused with “endemic,” but the two words have different meanings. While “epidemic” describes how far a specific outbreak of a disease has spread, the word"endemic" refers to the constant presence of a disease in a geographic population.
For example, chicken pox is considered endemic in the United States because it affects American school children at predictable rates.
The term “epidemic"is used in a couple of different ways, mainly to describe:
These usages are not wrong, but they can cause confusion.
Even when “epidemic” is used to define health issues, it may not accurately describe the scale of the disease or how quickly it is spreading.
In some cases, “epidemic” may fall short in describing the scale of the problem, and the word “pandemic” may be more fitting.
Disease Event Classification
Epidemiology is the branch of medicine that studies how often diseases occur in different groups of people and why.
In the United States, the Centers for Disease Control and Prevention (CDC) is the main body that collects and oversees epidemiological data. Among its many functions, the CDC is tasked with directing the appropriate response to a disease occurrence.
Therole of epidemiologyis to determine the disease prevalence (the number of people within a population who have the disease) and incidence (the number of new cases within a certain timeframe). These figures help direct the appropriate public health response.
There are several other ways an epidemiologist might describe a disease event:
What It Means When a Disease Is Endemic
Examples of Epidemics and Pandemics
Endemics and pandemics have occurred throughout human history, including these devastating and noteworthy outbreaks of diseases:
Summary
An epidemic is a disease outbreak that is rapidly spreading in a limited region. A pandemic is an epidemic that is actively spreading to multiple regions across the globe.
The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit ourcoronavirus news page.
17 Sources
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Centers for Disease Control and Prevention.What exactly is a pandemic?
Centers for Disease Control and Prevention.CDC’s response to the 2014-2016 ebola epidemic.
Association for Professionals in Infection Control and Epidemiology.Outbreaks, epidemics, and pandemics - what you need to know.
Chapter 1: What is epidemiology?. BMJ.Epidemiology for the uninitiated.
Riley LW.Differentiating epidemic from endemic or sporadic infectious disease occurrence.Microbiol Spectr. 2019;7(4):10.1128/microbiolspec.AME-0007-2019. doi:10.1128/microbiolspec.AME-0007-2019
Centers for Disease Control and Prevention (CDC).Tetanus surveillance and trends.
World Health Organization.Disease outbreaks.
Ancient History Encyclopedia.Justinian’s plague (541-542 CE).
New World Encyclopedia.Black death.
Centers for Disease Control and Prevention.1918 pandemic (H1N1 virus).
Voigt EA, Kennedy RB, Poland GA.Defending against smallpox: a focus on vaccines.Expert Rev Vaccines. 2016;15(9):1197-211. doi:10.1080/14760584.2016.1175305
World Health Organization.WHO Coronavirus (COVID-19) Dashboard.
World Health Organization.Emergencies: Coronavirus disease (COVID-19) pandemic.
TB Alliance.The pandemic.
World Health Organization. HIV.
Centers for Disease Control and Prevention.2009 H1N1 Pandemic (H1N1pdm09 virus).
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