The World Health Organization (WHO) on Wednesday declared the COVID-19 outbreak a pandemic, citing infections in over 121,000 people worldwide.
But what is a pandemic and how is it defined? According to the Centers for Disease Control, a pandemic refers to an epidemic that has spread over several countries or continents and usually affects a large number of people.
Until this point, WHO had categorized the spread of COVID-19 as a series of epidemics and not necessarily a worldwide issue.
An epidemic is defined as a sudden increase in the number of cases of a disease above what is normally expected from the population in that area.
The word pandemic sounds scary, but generally just refers to how many parts of the world are dealing with an elevated risk of the disease.
Pandemics must be fought at an international level where as epidemics are fought within that countries borders.
Government officials can also recommend people do not gather in mass in one location or at certain events.
Pandemics are also not a new phenomena. They have been part our society for centuries.
The CDC reports there were at least four influenza pandemics in the 20th century, with a single outbreak known as the Spanish flu causing over 21 million deaths globally from 1918 to 1919.
The most recent pandemic in the world was the H1N1 flu pandemic in 2009. This was also known as the swine flu.
It killed hundreds of thousands around the world, but the mortality rate was estimated at 0.02 percent.
For most people, the new coronavirus causes only mild or moderate symptoms. It can cause more severe illness including pneumonia in older adults and people with existing health problems.
The vast majority of people recover from the new virus within weeks.