Science
Fact-checked

At WiseGEEK, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is a Pandemic?

Michael Anissimov
Michael Anissimov
Michael Anissimov
Michael Anissimov

A pandemic is a global outbreak of a serious disease that exceeds the "normal" levels of mortality and infection levels for typical disease. In this regard, the definition of a pandemic is partially subjective, but in most cases, the difference between the normal background state and a pandemic state is strikingly obvious. Throughout history, pandemics have been the worst killers of human beings, killing more people than all wars and accidents in modern history combined. Only in the last 90 years or so does it seem that historical pandemics are mostly under control, although the HIV virus, which emerged in the 1980s, has killed millions, and continues to be a serious problem to this day.

Historically, the largest pandemics have been due to smallpox, influenza, cholera, typhus, and bubonic plague. The greatest pandemic in history is often cited as the Black Death (thought to be bubonic plague), which claimed 75 million lives and killed about a third of the population of Europe and China in the late 1340s. Recovery took more than a generation. The native Americans and native Australians were fortunate that these populations were disconnected from those of Africa and Eurasia at the time. The Black Death was spread by infected rats.

Rats are implicated in several historical pandemics.
Rats are implicated in several historical pandemics.

Another massive pandemic, the Spanish flu, spread worldwide in 1918, immediately after WWI, killing 50-100 million people and rivaling the intensity of the Black Death. This flu was unusual in that it killed people in the prime of their lives rather than just the old or infants. Deaths are thought to have been caused by cytokine storms, a hyperactive immune system response that leads to the death of the organism it is meant to protect. In a cytokine storm, immune cells clog the body so rapidly that they do even more damage than the flu itself.

Cholera, an infection of the small intestine, was one of the largest pandemics in history.
Cholera, an infection of the small intestine, was one of the largest pandemics in history.

When they occur, pandemics have radically altered the course of history and changed world events. If the Black Death had not occurred in Europe, economic and technological progress might have been accelerated and Columbus may have reached the Americas as much as a hundred years earlier. Today, many governments fear a new pandemic caused by a mutation of the avian flu, and hundreds of millions of doses of immunization shots have been stockpiled.

Michael Anissimov
Michael Anissimov

Michael is a longtime WiseGEEK contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

Learn more...
Michael Anissimov
Michael Anissimov

Michael is a longtime WiseGEEK contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

Learn more...

Discussion Comments

anon31100

What will happen if the health organization raises the swine flue alert to level 6?

josephkoenig

What is the impact on other countries economies, everyday life, and politics?

Post your comments
Login:
Forgot password?
Register:
    • Rats are implicated in several historical pandemics.
      By: Ilia Shcherbakov
      Rats are implicated in several historical pandemics.
    • Cholera, an infection of the small intestine, was one of the largest pandemics in history.
      By: psdesign1
      Cholera, an infection of the small intestine, was one of the largest pandemics in history.
    • A mutation of the avian flu virus could cause a modern-day pandemic.
      By: robyelo357
      A mutation of the avian flu virus could cause a modern-day pandemic.
    • Cytokine storm is the body's over-reaction to infection.
      By: psdesign1
      Cytokine storm is the body's over-reaction to infection.
    • Proper hand washing reduces the likelihood of a global outbreak of disease or a pandemic.
      By: byrdyak
      Proper hand washing reduces the likelihood of a global outbreak of disease or a pandemic.