The World Health Organization (WHO) has applied the official label of pandemic to COVID-19, the disease caused by the novel coronavirus.
The virus, which originated in Wuhan, China, has infected more than 120,000 people worldwide and killed more than 4,200, according to the global agency.
In Canada, there were 103 confirmed cases as of Thursday morning, with one death in British Columbia.
Health officials are bracing for the continued community spread of the virus around the world. According to the WHO, at least 45 countries have implemented travel and health measures to specifically deal with the spread of the novel coronavirus.
Pandemic is a scary word. But what does it mean? And how did we get here?
What is the difference between an outbreak, an epidemic and a pandemic?
It’s a matter of scale, and the difference between all these terms can be traced through the history of the novel coronavirus.
An outbreak is when a disease infects a lot of people in one area in a short amount of time. Pandemics start as outbreaks. The novel coronavirus was initially an outbreak in Wuhan when the first few dozen cases were confirmed.
An outbreak becomes an epidemic when there’s a sudden increase in the number of cases. To get really technical, the WHO defines an epidemic as “the occurrence in a community or region of cases of an illness ... clearly in excess of normal expectancy.”
So for the past few weeks, it’s been fair to say there have been localized coronavirus epidemics in places like China, South Korea, Italy and Iran.
But when does an epidemic cross over into a pandemic? That’s where we are now.
The U.S. Centers for Disease Control and Prevention defines a pandemic as an epidemic that has “spread over several countries or continents, usually affecting a large number of people.”
WATCH: Doctor explains difference between epidemic and pandemic. Story continues below.
So technically speaking, a pandemic is what happens when an epidemic goes worldwide. It’s important to know that it has nothing to do with the severity of the disease, but moreso its distribution.
The actual declaration of a pandemic is a bit trickier. People who contract the disease in epidemic areas and travel back to their home country don’t count towards defining a pandemic. It’s only when community transmission — spread from one person to another without direct links to travel in affected areas — is prevalent around the world that a pandemic is declared.
Canada is one of several countries already reporting cases of community transmission.
What are some notable pandemics of the past?
The most notable example of a global pandemic was the 1918 Spanish influenza, which infected around 500 million people worldwide, or a third of the global population at the time. Its spread was largely fuelled by troop movements across Europe during the First World War. An estimated 50 million people — or one in 10 cases — died.
WATCH: First cases of Spanish flu reported in 1918. Story continues below.
While there were several other influenza pandemics throughout the 20th century, the most recent was 2009’s H1N1, also known as “Swine Flu.” The U.S. Centers for Disease Control estimated that between 150,000 to 575,000 people died worldwide during that pandemic.
However, the WHO was criticized for causing panic by declaring it a pandemic in the first place.
The SARS epidemic in 2001 was not designated a pandemic by the WHO. While it affected 26 countries and 8,000 people, it was quickly contained to a few impacted countries.
Even though COVID-19 was declared a pandemic and SARS was not, that doesn’t mean it’s objectively “worse.” It just means it spread farther and faster. The mortality rate for SARS patients was around 10 per cent, while the documented death rate of COVID-19 is around 3.4 per cent.
What changes now?
According to the WHO, the existing health advice for managing the disease remains consistent.
“Describing the situation as a pandemic does not change WHO’s assessment of the threat posed by this coronavirus,” WHO director-general Tedros Adhenom Ghebreyesus said at a news conference Wednesday.
“It doesn’t change what WHO is doing, and it doesn’t change what countries should do.”
Ghebreyesus said the virus can be controlled if countries continue to take adequate measures.
“The challenge for many countries who are now dealing with large COVID-19 clusters or community transmission is not whether they can do the same — it’s whether they will,” Ghebreyesus said.
The Canadian government pledged $1 billion on Wednesday to support the provinces and territories in addressing COVID-19, including money for vaccine research, medical equipment, and masks for health-care workers.
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