COVID-19′s rapid spread has raised alarms about the growing risk to vulnerable people around the world. Here’s what you need to know about how pandemics are defined, and what to do if there is one

COVID-19′s rapid spread has raised alarms about the growing risk to vulnerable people around the world. Here’s what you need to know about how pandemics are defined, and what to do if there is one

COVID-19s rapid spread around the world has raised alarms that a pandemic might be imminent, potentially putting vulnerable people at deadly risk. But what is a pandemic, and what happens if this new coronavirus is declared one? Heres what you need to know.
What pandemic means
An electron-microscope image shows, SARS-CoV-2, the virus that causes the coronaviral illness known as COVID-19.
U.S. National Institutes of Health/AFP via Getty Images
Pandemic comes from the Greek words pan, all, and demos, people. Health agencies use it to refer to the worldwide spread of a previously unknown disease. But since theres no globally accepted definition of worldwide How many countries? How many continents? a disease may sometimes be treated as a pandemic in one jurisdiction, but not another. Australia, for instance, effectively started treating the current coronavirus as a pandemic when the World Health Organization hadnt yet called it that.
The last generally agreed-upon pandemic was 2009s spread of H1N1, also called swine flu. When WHO revised its guidelines for pandemics at the time, it didnt include a single, quotable definition of what a pandemic is. Instead, it described six phases from initial infections to pandemic, each giving national health authorities advice about what to do as the urgency increased:
Story continues below advertisement

  • 1: Animals are infected with a disease, but not humans.
  • 2: Some humans are infected with the disease.
  • 3. Small clusters of the disease have been reported, but not human-to-human transition.
  • 4. Human-to-human transmission has been verified and is able to cause sustained community-level outbreaks.
  • 5. The virus has caused sustained community-level outbreaks in two or more countries in one WHO region. This stage can also serve as a signal that a pandemic is imminent.
  • 6. Additionally to 5, the disease has caused sustained outbreaks in at least one other country or WHO region. Its only at this stage that it can be considered a pandemic.

Later revisions to the influenza guidelines simplified and blended these stages. First theres an interpandemic phase between outbreaks of a disease; then an alert phase, when a new disease type is observed in humans; then a pandemic phase, when the disease has spread globally; and finally a transition phase, when the global risk subsides. WHO risk-management documents acknowledge that the situation can quickly change between the stages. Ultimately, the declaration of a pandemic is up to the WHO director-general, based on risk assessment and appropriate to the situation.
Tedros Adhanom Ghebreyesus is Director-General of the World Health Organization.
Salvatore Di Nolfi/Keystone via AP
How is a pandemic different from an epidemic or outbreak?
An outbreak is the emergence of a disease in a particular place, while an epidemic is a dramatic, sudden or unexpected rise in infections within a country or region. When COVID-19 initially emerged in the Chinese city of Wuhan last December, that was an outbreak, but by the point where it had infected thousands in Hubei province and its environs, it was an epidemic. If a new disease becomes so established that theres a baseline level that is considered normal, then its endemic: The common cold, for instance, is caused by other types of coronaviruses that nearly everybody has at some point. And if a disease is endemic but causes a sustained level of infection higher than health officials think it should be, its hyperendemic.
A key stage in the transition from outbreak to epidemic to pandemic is community spread, meaning the disease is present in patients who hadnt recently travelled to an infected area and have had no known exposure to another infected person. In other words, once a countrys health officials can no longer keep track of where every case originates, its too late to completely stop it from reaching that countrys general population.
Muslim pilgrims wear masks at the Grand Mosque in Saudi Arabia’s holy city of Mecca on Feb. 27, after the Saudi government, fearing the spread of the coronavirus, suspended visas to visit Islam’s holiest sites.
ABDULGANI BASHEER/AFP via Getty Images
Does pandemic mean its deadlier?
Yes and no. Pandemic refers to where the disease has spread, not how many people its infected; however, obviously, those two things are interrelated. In the first two months after COVID-19 was discovered in China, health officials had a more or less clear idea of where the disease was likely to come from, which meant they could target their messages to people travelling from those places. But in a pandemic situation, the disease could be introduced to an uninfected population from lots of different places, making it harder to stop and more likely to infect the most at-risk groups: elderly people, patients with pre-existing medical conditions and health-care workers.
Where is COVID-19 now?
1 to 910 to 99101 to 1000Over 1000 cases
What would a COVID-19 pandemic look like?
COVID-19 is caused by a type of coronavirus, officially named SARS-CoV-2, that is in the same family of viruses as SARS and MERS. An infected person may feel feverish, tired or congested, or have a sore throat or general aches. Some people are infected but dont show any symptoms, and most recover from the virus without special treatment. But in extreme cases, pneumonia sets in, sometimes with fatal results.
HOW DOES CORONAVIRUS
INFECT A PERSON?
Human coronaviruses most commonly spread from an infected person to others through:
The air by coughing and sneezing
Close personal contact, such as touching or shaking hands
Touching the eyes, nose or mouth after touching an infected surface
Rarely, fecal contamination
WHAT ARE THE SYMPTOMS OF THE VIRUS?
Headache
Runny nose
Sore throat
Cough
Fever
In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death
SOME FACTS ABOUT THE VIRUS
Belongs to large family of viruses that cause illnesses ranging from common cold to more severe diseases such as MERS and SARS
Coronaviruses are zoonotic, meaning they are transmitted between animals and people
There are no specific treatments for coronaviruses, but symptoms can be treated
MURAT YÜKSELIR / THE GLOBE AND MAIL, SOURCE: Centers for Disease Control and Prevention, Health Canada, WHO
HOW DOES CORONAVIRUS INFECT A PERSON?
Human coronaviruses most commonly spread from an infected person to others through:
The air by coughing and sneezing
Close personal contact, such as touching or shaking hands
Touching the eyes, nose or mouth after touching an infected surface
Rarely, fecal contamination
WHAT ARE THE SYMPTOMS OF THE VIRUS?
Headache
Runny nose
Sore throat
Cough
Fever
In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death
SOME FACTS ABOUT THE VIRUS
Belongs to large family of viruses that cause illnesses ranging from common cold to more severe diseases such as MERS and SARS
Coronaviruses are zoonotic, meaning they are transmitted between animals and people
There are no specific treatments for coronaviruses, but symptoms can be treated
MURAT YÜKSELIR / THE GLOBE AND MAIL, SOURCE: Centers for Disease Control and Prevention, Health Canada, WHO
HOW DOES CORONAVIRUS INFECT A PERSON?
Human coronaviruses most commonly spread from an infected person to others through:
The air by coughing and sneezing
Close personal contact, such as touching or shaking hands
Touching the eyes, nose or mouth after touching an infected surface
Rarely, fecal
contamination
COMMON SIGNS OF INFECTION
Headache
In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death
Runny nose
Sore throat
Cough
Fever
SOME FACTS ABOUT THE VIRUS
Belongs to large family of viruses that cause illnesses ranging from common cold to more severe diseases such as MERS and SARS
Coronaviruses are zoonotic, meaning they are transmitted between animals and people
There are no specific treatments for coronaviruses, but symptoms can be treated
MURAT YÜKSELIR / THE GLOBE AND MAIL, SOURCE: Centers for Disease Control and Prevention, Health Canada, WHO
If this is a pandemic, what do I do?
Canada already has a detailed pandemic plan ready for the coronavirus, federal Health Minister Patty Hajdu says. You may have already seen its initial steps: Increased surveillance for the disease at hospitals and airports, warnings to the public about the symptoms of the disease. Most of this plan is meant for health officials and governments to co-ordinate their available resources, but it may involve actions from the public such as staying home from work or school. One thing you should definitely do is wash your hands often and properly; heres a video primer from the WHO on how to do that.
For now, Ms. Hajdu has said Canadians can prepare by making sure they have an adequate supply of food and prescription drugs. If cases spread at the local level, governments might also consider things like closing schools or gathering volunteers to open reception centres for people who are sick and need help, but not necessarily hospitalization. If things get really bad, and provincial health-care systems have to start doing triage to allocate services, thats when public-health agencies may consider cancelling major gatherings like festivals and sports events. If this does happen, its important for Canadians to follow the agencies advice.
Story continues below advertisement
The plan also outlines what happens when the pandemic dies down and things start to get back to normal. First is to prepare for a possible resurgence and restock supplies. Health systems should also put together immunization programs, if a vaccine exists, and evaluate the psychological effect of the outbreak on the public.
More reading
Explainers and in-depth coverage
The COVID-19 coronavirus: What we know so far about the new disease
What can I do about COVID-19? A guide for Canadians of whats helpful, and whats not
New coronavirus tests scientists ability to tangle with an evolutionary trickster
Commentary and analysis
André Picard: How prepared is Canadas health-care system to handle a potential coronavirus pandemic?
André Picard: What happens if the coronavirus cant be contained?
Adrian Lee: For Chinese-Canadians like me, coronavirus is just the latest strain of infectious fear weve faced
Compiled by Globe staff
With reports from The Canadian Press and Carly Weeks
Our Morning Update and Evening Update newsletters are written by Globe editors, giving you a concise summary of the days most important headlines. Sign up today.

Share