What is a pandemic and how many has the world experienced?

Since 1900, there have been eight pandemics declared in the world.


On Wednesday, the World Health Organization (WHO) officially declared the novel coronavirus, or COVID-19, a pandemic.

What is a pandemic?

WHO considers a pandemic a global outbreak of an infectious disease.

In designating COVID-19 a pandemic, the organization said the virus had grown beyond containment worldwide but cautioned the public that this assessment doesn't imply the organization has accepted that "the fight is over."

"We cannot say this loudly enough, or clearly enough, or often enough: All countries can still change the course of this pandemic," the organization said.


How many pandemics has the world experienced?

Since the Middle Ages, there have been about a dozen notable pandemics, including COVID-19.

The first of which, according to data compiled for the World Bank, was the Bubonic plague. It killed 30% to 50% of Europeans in the 1300s.

Then the introduction of smallpox in the Americas came in the 1500s. The first global pandemic was declared in 1881 when cholera killed more than 1.5 million people worldwide.

Since 1900, there have been eight pandemics. The 1918 Spanish flu, a global pandemic, killed between 20 million and 100 million people worldwide.

The HIV/AIDS pandemic, which was declared in 1981, is still considered an active pandemic. It's resulted in 36.7 million deaths, according to data from the National Institutes of Health.

There have also been two epidemics that were not declared official pandemics — MERS in 2012, which impacted 22 countries but had fewer than 2,000 cases, and West Africa Ebola in 2013, which had nearly 30,000 cases but only impacted 10 countries.

At the time of WHO's pandemic designation, COVID-19 had infected more than 118,000 cases in 114 countries, and killed 4,291 people, according to WHO.