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What exactly is a pandemic?

Donna Christiano writer headshot By | Updated on March 23, 2020
Medically reviewed by Lindsey Hudson, APRN, NP-C

Pandemic is a pretty scary word. Delete just a few letters and you’re left with panic—an apt description for how much of the world is feeling about the new coronavirus that emerged late last year in Wuhan, China. The new virus, technically called SARS-CoV-2, is now threatening global health, sweeping across continents and through communities. It causes a respiratory disease dubbed coronavirus disease 2019, or COVID-19. 

What is a pandemic?

A pandemic is the widespread outbreak of a new disease that crosses borders and oceans, reports the World Health Organization (WHO). Pandemics are caused by viruses humans haven’t encountered before (many emerge from animals) or bacteria that are resistant to antibiotics. Pandemics don’t have to technically reach all corners of the world (although many do, thanks to international travel). They do affect many people and are generally found on two or more continents. 

Coronaviruses are nothing new—in fact, some cause the common cold. But, a novel strain has caused a global outbreak, infecting more than 100,000 people in dozens of countries, from Iran to Italy to India. If you think that sounds like a pandemic, you wouldn’t be alone.

On Mar. 11, 2020, the WHO declared COVID-19 officially a pandemic. 

Pandemic vs. epidemic

While both pandemics and epidemics involve a large number of people, there is a difference. An epidemic occurs when an infectious disease (e.g., influenza, HIV, or Ebola) spreads quickly and sometimes suddenly to a lot of people—more than what might ordinarily be expected at that time and in that area, explains the Association for Professionals in Infection Control and Epidemiology. A pandemic, on the other hand, is a kind of supersize epidemic, but with differences. When compared to epidemics, pandemics:

  • Affect a greater number of people
  • Have a global spread
  • Cause more deaths
  • Involve a new virus or antibiotic resistant bacteria

And while things like cancer, obesity, and even opioid abuse are often called epidemics, technically they aren’t as they’re not caused by infections.

Examples of pandemics

Pandemics have been around for centuries—and centuries and centuries. One of the most famous pandemics was the bubonic plague (or Black Death), which occured in the Middle Ages and killed millions. Pandemics from the 20th century mostly centered around flu viruses involving influenza A and include:

  • The 1918 Spanish flu, which killed 50 million people worldwide
  • The Asian influenza of 1957
  • The Hong Kong influenza of 1968

Notable 21st century pandemics include:

  • SARS (severe acute respiratory syndrome): This pandemic, caused by another coronavirus, started in China in 2002 and ended up infecting more than 8,000 people across Asia, Europe, and North and South Americas. In the United States, the Centers for Disease Control and Prevention (CDC) says, 115 people from 29 states were sickened with SARS.
  • H1N1 virus: This influenza virus—also known as the “swine flu”—first appeared in 2009 and had not previously been seen in animals or humans. From April 2009 to April 2010, the CDC estimates 284,000 people worldwide died from H1N1. The H1N1 flu pandemic is the most recently declared influenza pandemic affecting the United States.
  • HIV/AIDS is an ongoing pandemic. In 2018, nearly 38 million people around the world were living with HIV/AIDS.

Is the coronavirus a pandemic?

As of March, 2020, WHO classified COVID-19 as a global pandemic. It’s definitely producing more worry than the flu virus, though, which also causes widespread disease outbreak and sometimes death but isn’t (at least this season) the result of a novel virus. 

“COVID-19 appears to be more virulent [than influenza], spreads easily, and is difficult to contain, since transmission occurs among people who have mild or no disease,” explains Jana Shaw, MD, associate professor of pediatrics and epidemiology at Upstate Golisano Children’s Hospital in Syracuse, New York. 

How to survive a pandemic

There’s no good way of predicting how a novel virus like SARS-CoV-2 may play out. Pandemics can last from months to years. Outbreaks of SARS, for example, were contained in six months. HIV/AIDS is still ongoing. According to news reports, cases of COVID-19 in China and South Korea seem to be slowing even while it ratchets up in other parts of the world. Some are hopeful that the virus may die down, as the flu and other viruses do, as warmer weather approaches, but many health experts caution that there are just too many unknowns with this new virus, and it will take serious and consistent public health measures (and not the weather) to effectively contain it. 

And how might this new coronavirus outbreak be contained? Governments work to fight back pandemics by issuing quarantines (Italy is now under “lockdown”), supplying diagnostic tests to pinpoint those who are infectious, restricting travel and developing vaccines when possible. But that all takes time and cooperation. What can you do to help protect yourself from this novel coronavirus in the meantime?

First, don’t panic. This new coronavirus, which, although spreading, is not rampant in the United States, poses the biggest threat to those who are elderly or who have underlying medical conditions such as heart disease or diabetes. Secondly, understand that COVID-19 is a disease that’s spread much like influenza and other infectious respiratory illnesses—through the droplets infected people release when they sneeze or cough. The CDC recommends:

  • Staying home if you’re sick.
  • Avoiding close contact with people when possible (health officials advise staying back 6 feet).
  • Keeping hands away from your nose, mouth, and eyes.
  • Sneezing or coughing into a tissue (and then throwing it away) or a sleeve when a tissue is not available.
  • Washing your hands frequently with soap and water for at least 20 seconds. This is especially important after using the bathroom, before eating or after sneezing or coughing. Use hand sanitizer with at least 60% alcohol when soap and water aren’t available.
  • Periodically wiping hard surfaces—counters, door knobs, etc. The CDC recommends using regular household detergent and water and then a disinfectant. The Center for Biocide Chemistries has a list of products that can effectively fight the coronavirus.
  • Skipping the face mask. There’s no evidence showing it will protect you from germs (although it can help reduce spread of the virus  if you’re sick). A face mask could even make you sick if you touch the germy outside and then touch your face.

The better you are at avoiding the droplets, the better you’ll be at avoiding infection.