Know the Facts about Coronavirus Disease 2019 (COVID-19)

Pandemic vs. Epidemic: What's the Difference?

COVID-19 was declared a global pandemic by the WHO. But what does that mean and how is a pandemic different from an epidemic?

March 27, 2020

The World Health Organization declared COVID-19 a pandemic because of the unusually fast rate in which the virus is spreading. The novel coronavirus has infected more than half a million people worldwide and is present in more than 175 countries. It has killed more than 22,000 people and has a global fatality rate of 4.4%. But what’s the difference between a pandemic and epidemic, and how does designating pandemic status impact COVID-19?

What is an epidemic?

Let's start with an epidemic. An epidemic is an outbreak of a disease that spreads quickly and affects many individuals at the same time. An outbreak occurs when there is a sudden increase in the number of cases of a disease. It generally describes an increase that was not anticipated. An outbreak can occur in a community, geographical area or several countries.

Epidemic is often used broadly to describe any problem that has grown out of control. During an epidemic, the disease is actively spreading.

Examples of past epidemics are the 1918 Spanish flu, the measles outbreak from 1981 to 1991, and a 2014 case of whopping cough. 

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What is a pandemic?

A pandemic is a type of epidemic that relates to geographic spread and describes a disease that affects an entire country or the whole world. 

An epidemic becomes a pandemic when it spreads over significant geographical areas and affects a large percent of the population.

In short, a pandemic is an epidemic on a national or global level.

Examples of past pandemics are the flu pandemic of 1968, the HIV/AIDS pandemic, and the bubonic plague.

How is a pandemic different:

  • Affects a wider geographical area, often worldwide
  • Infects a larger number of people
  • Often caused by a new virus or a new strain of virus that has not circulated within people for a long time
  • Humans have little to no immunity against the virus and it spreads quickly
  • Causes more deaths
  • Often creates social disruption and economic loss

The terms pandemic and epidemic are never used to indicate the severity of the disease, only the degree at which the disease is spreading.

Read why social distancing is so important

Why declare a pandemic?

Declaring a pandemic allows national and global public health agencies to respond to the situation at a higher degree.

The use of the term also highlights the importance of countries working together in the effort to control the pandemic. More than anything, declaring a pandemic works to raise awareness about the problem and increase measures to control it.

Learn the differences between COVID-19 and the flu

COVID-19 pandemic status

COVID-19 is declared a pandemic because of the speed at which it has spread globally.

The World Health Organization declares COVID-19 to be a controllable pandemic and continues to provide advice on precautionary practices and ways to stop the spread of the disease.

Learn more about COVID-19 by visiting our resource page.

Know the Facts of COVID-19

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