A pandemic or a “global pandemic” is an epidemic that’s spread over multiple countries or continents. While an epidemic is a disease that affects a large number of people within a community, population, or region.
The first recorded instance of the word epidemic being used to refer to a widespread disease is around the year 430 BC when Hippocrates included it in a medical treatise.
Epidemics can occur:
- when an infectious agent (such as a virus) suddenly becomes much more prevalent in an area where it already existed
- when an outbreak spreads throughout an area where the disease wasn’t previously known
- when people who weren’t previously susceptible to an infectious agent suddenly start getting sick from it
Smallpox, cholera, yellow fever, typhoid, measles, and polio are some of the worst epidemics in American history. Today, HIV and drug-resistant tuberculosis are considered epidemics.
Today, we use the word epidemic in casual conversation, to refer to almost anything negative. For example, laziness, gun violence, and opioid use have all been called epidemics in popular media.
COVID-19 is a pandemic because it has spread over multiple countries.