Coronavirus Is Now Officially Being Called a Pandemic

Learn the difference between a pandemic, an epidemic, and an outbreak—and what it means for coronavirus.

UPDATE (Mar. 11): The World Health Organization (WHO) has officially upgraded the coronavirus to a "pandemic":

The original article from Mar. 9 appears as follows:

It looks like coronavirus is now being called a pandemic by multiple outlets worldwide, including CNN and New Scientist. The World Health Organization (WHO), however, is refraining from using the word "pandemic" in reference to coronavirus. In a media briefing on Monday, Tedros Adhanom Ghebreyesus, PhD, MSc, Director-General of WHO, said, "Now that the virus has a foothold in so many countries, the threat of a pandemic has become very real." Since coronavirus will very likely continue to spread over the next few weeks and months, not dissipate, it is nearly a certainty that if it's not already considered a pandemic, it's only a matter of time.

So what's the difference between an outbreak, an epidemic, and a pandemic? As CNN's Chief Medical Correspondent Sanjay Gupta, MD, explained during his appearance on CNN's New Day on Monday, Mar. 9, it comes down to the following:

What's an outbreak?

According to Merriam-Webster: "An outbreak is a sudden localized incidence of a disease. An 'outbreak' can become an epidemic if it the spread becomes more severe, infecting more people over a wider area. Finally, if the disease continues to spread uncontrolled, it can become a pandemic, where the 'epidemic' has become widespread over large geographic areas and has infected very high numbers of individuals."

What's an epidemic?

According to WHO, an epidemic is defined as: "The occurrence in a community or region of cases of an illness, specific health-related behaviour, or other health-related events clearly in excess of normal expectancy. The community or region and the period in which the cases occur are specified precisely. The number of cases indicating the presence of an epidemic varies according to the agent, size, and type of population exposed, previous experience or lack of exposure to the disease, and time and place of occurrence."

What's a pandemic?

According to Gupta, a pandemic must meet these three qualifications:

  • Virus that can cause illness or death
  • Sustained person-to-person transmission
  • Spread throughout the world

Gupta told New Day that he suspects WHO is trying to find a "balance between not wanting to cause panic and trying to look at the data, but when we look at these numbers now and look at what's happening around the world, it's important, I think, to call [coronavirus] a pandemic."


In a post on CNN, Gupta furthers explains that he "spent the last several days speaking to public health leaders, epidemiologists, and clinicians about the terminology. While some were understandably conservative, everyone agreed that we are now in a pandemic."

Tom Frieden, MD, former director of the Centers for Disease Control and Prevention (CDC) and current president and CEO of Resolve to Save Lives, told Gupta: "It has been clear for several weeks that this would become a pandemic and now it has … Every community in every country needs to prepare so that we can reduce both the health and societal consequences. Some pandemics are only mild or moderate, and it is still not certain how severe this will be."

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