The Real Difference Between A Pandemic And An Epidemic

It's pretty clear that information about the COVID-19 coronavirus is, well, going viral. As is the virus itself. Health authorities have repeatedly requested that people do their best to keep panic at bay, and wash their hands twenty seconds at a time: you can recite the spoken introduction to Star Trek while you're doing it, and it'll be just about enough time. Nonetheless, a lot of people seem to have become ill in a rather short period of time. Semantics are being thrown around willy-nilly, but exact wording does count, as does accuracy, so what is going on here? 

Although the situation seems to change fairly quickly, here are some factoids as of March 15th, 2020, courtesy of For starters: the World Health Organization (WHO) declared the situation a "pandemic" on March 11. But what comes first is an epidemic, according to David Jones, an MD, PhD, and professor of the culture of medicine at Harvard University. "A pandemic is when an epidemic spreads between countries," says the good doctor. 

Stay calm, and wash your hands

According to WHO, this is the first pandemic spread by a coronavirus. The Centers for Disease Control and Prevention are quoted as saying that an epidemic is "a sudden increase in the number of cases of a disease — more than what's typically expected for the population in that area." That word sudden is important, here, according to U.S. News: "Frequently, the rise in cases happens quickly."

So, to be clear, an epidemic refers to an unusually large number of cases in one area. A pandemic, then, is when those unusually large numbers include a spread into other countries. If you're thinking that the language isn't exact, you're exactly right. There's no actual figure attached to either definition. It's a judgment call on the part of health authorities and governments. There have been a number of health situations defined as epidemics before, such as not-so-uncommon flu epidemics, or the spread of 2003 SARS virus. There have also been a number of pandemics, as Live Science explains — most recently, the H1N1 swine flu pandemic of 2009.

Regardless of how widespread a disease you're facing, though, proper hygiene — that good old handwashing for twenty seconds thing — is crucial to staying healthy and avoiding sickness. Or, depending on where you're standing, a pandemic.