The World Health Organization declared the novel coronavirus a pandemic on Wednesday as it spreads in more than 100 countries around the world.
The WHO defines a pandemic as "the worldwide spread of a new disease." The determination is based on the geographic spread of a disease, the severity of illnesses it causes, and its effects on society.
COVID-19, the illness caused by the new coronavirus, has sickened more than 121,000 people and killed over 4,300 people.
On Wednesday, the WHO said it was deeply concerned by the "alarming levels of inaction" about the coronavirus outbreak but described the term "pandemic" as both a "characterization" and a "call to action," not an excuse to give up.
"If countries detect, test, treat, isolate, trace, and mobilize their people in their response, those with a handful of cases can prevent those cases from becoming clusters and those clusters from becoming community transmissions," the WHO's director-general, Tedros Adhanom Ghebreyesus, told reporters in Geneva.
The word "pandemic" comes from the Greek "pan" and "demos," meaning "all the people," but using it does not change that much from a pragmatic, disease-fighting perspective. The WHO had been hesitant to refer to this coronavirus outbreak as a pandemic in recent weeks, fearing that the moniker would lead to widespread panic and saying it was perhaps not yet warranted.
"If this was an influenza epidemic, we would have expected to see widespread community transmission across the globe by now, and efforts to slow it down or contain it would not be feasible," Tedros said last week. "But containment of COVID-19 is feasible and must remain the top priority for all countries."
The organization in January declared the coronavirus outbreak a "global health emergency," its highest level of alarm, which it reserves for the most serious, sudden, unexpected outbreaks that cross international borders and might require a coordinated response between countries. This is the first time the pandemic designation has been used for a coronavirus.
"There's no numerical definition of a pandemic — like beauty, it's in the eye of the beholder," William Schaffner, an infectious-disease specialist at the Vanderbilt University School of Medicine, previously told Business Insider.
An epidemic, by contrast, refers to a more localized or regional outbreak rather than a global one.
