The World Health Organization (WHO) on Wednesday declared the rapidly spreading coronavirus outbreak a pandemic, acknowledging that the virus will likely spread to all countries on the globe.

In the past two weeks, the number of cases of COVID-19 outside China has increased 13-fold, and the number of affected countries has tripled, WHO Director-General Tedros Adhanom Ghebreyesus noted at the media briefing yesterday. 

There are 118,000 cases, more than 4,000 deaths, the agency said, and the virus has found a foothold on every continent except for Antarctica.

"We have never before seen a pandemic sparked by a coronavirus.  And we have never before seen a pandemic that can be controlled at the same time," Ghebreyesus said.

The WHO has stressed that using the word “pandemic” does not signal a change in its advice. It is still urging countries to detect, test, treat, isolate, trace and mobilize their people.

"Describing the situation as a pandemic does not change WHO's assessment of the threat posed by this coronavirus. It doesn't change what WHO is doing, and it doesn't change what countries should do."

If countries detect, test, treat, isolate, trace and mobilize their people in the response, those with a handful of novel coronavirus cases can prevent those cases becoming clusters, and those clusters becoming community transmission, Ghebreyesus said.

"Several countries have demonstrated that this virus can be suppressed and controlled," Ghebreyesus said.

Recall, the WHO in January declared the novel coronavirus outbreak a public health emergency of international concern. 

According to the WHO, a pandemic is declared when a new disease for which people do not have immunity spreads around the world beyond expectations.

A pandemic is a disease epidemic that has spread across a large region; for instance multiple continents, or worldwide.  A widespread endemic disease that is stable in terms of how many people are getting sick from it is not a pandemic. Further, flu pandemics generally exclude recurrences of seasonal flu. Throughout history, there have been a number of pandemics, such as smallpox and tuberculosis.  One of the most devastating pandemics was the Black Death, which killed an estimated 75–200 million people in the 14th century.  The current pandemics are HIV/AIDS and coronavirus disease 2019 (COVID-19).  Other recent pandemics include the 1918 influenza pandemic (Spanish flu) and the 2009 flu pandemic (H1N1).