TORONTO -- While health authorities provide daily updates and governments share strategies to deal with the worsening COVID-19 pandemic, some of the medical terminology and scientific jargon may be confusing.

To make sense of it all, has created a glossary of terms that will help understanding of how the world is dealing with the viral outbreak.


Asymptomatic (Symptomatic)

An individual is asymptomatic when they don’t show any symptoms. Conversely, someone is symptomatic when they do exhibit symptoms.

Case Fatality Rate

The case fatality rate (CFR), sometimes called the fatality rate, is the term used to describe the proportion of people who have died from the disease among the total infected population.

It is different from the mortality rate, which measures the proportion of deaths in the total population and not just those who are infected.

Community transmission

Community transmission occurs when a virus starts appearing in people who haven’t had any known contact with an infected individual or travelled to an area where it is present.

Contact tracing

According to the World Health Organization, contact tracing is a monitoring process that involves identifying all of the people an infected person was recently in contact with, informing those contacts about the virus and what they should do, and conducting regular follow-ups with them.


Coronaviruses (CoV) are a large family of viruses that cause a range of illnesses ranging from the common cold to more severe diseases, such as COVID-19, according to the World Health Organization.

These viruses typically affect the respiratory system and symptoms often include fever, cough, shortness of breath, and breathing difficulties. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death.


COVID-19 is the infectious disease caused by the most recently discovered coronavirus.

According to the World Health Organization, the “CO” stands for corona, “VI” for virus, “D” for disease, and 19, which indicates the year the new illness appeared.


An epidemic is a large outbreak of a disease in a short period of time. Epidemics often happen when a new disease emerges or if something happens to make people less immune to a disease.

The World Health Organization said the number of cases in an epidemic can vary according to the types of disease and population that is exposed.

Flattening the curve

When health officials say they’re focusing on “flattening the curve,” it means they’re putting in place interventions and restrictions to slow the spread of a virus so there isn’t a large spike of cases in a short period of time. The intention is to keep the number of infections manageable so that health-care systems aren’t overwhelmed.


The incubation period is the amount of time it takes for an infected person to start showing symptoms, if there are symptoms. For COVID-19 specifically, the WHO says the incubation period is estimated to be between one to 14 days.


In response to the COVID-19 pandemic, many governments around the world have initiated lockdowns in cities, regions, or the entire country.

While there are variations on the specific measures, generally speaking, these have included government-imposed restrictions on movement and closures of non-essential businesses.

In some countries people who ignore the rules can be subject to fines or even jail time.

N95 mask (respirator)

While many people are using facemasks as a physical barrier to prevent the spread of COVID-19, others have resorted to N95 respirators.

N95 respirators are respiratory protective devices designed to fit closely to the face and provide efficient filtration of airborne particles. The N95 designation means it can block at least 95 per cent of very small particles.

Non-essential/essential services

As more governments enact lockdown measures to prevent the spread of the novel coronavirus, certain businesses and services have been forced to close because they have been deemed non-essential.

While the definition can vary depending on the region, for the most part, essential services typically include health-care systems, grocery stores, pharmacies, transportation networks, gas stations, and sanitation services.

Non-essential services typically include recreational, leisure and entertainment activities, as well as other retail businesses. 


A pandemic is typically declared when an epidemic has spread to multiple continents or countries. It has sometimes been called a “global epidemic.”

On March 11, the World Health Organization declared the spread of COVID-19 a pandemic.


In Canada, PHAC is an abbreviation of the Public Health Agency of Canada. It’s a federal government agency responsible for public health, emergency preparedness and response, and infectious disease control and prevention.

In the United States, the equivalent is the Centers for Disease Control and Prevention (CDC).

Globally, the World Health Organization (WHO) is the leading health agency of the United Nations that is providing leadership during the COVID-19 pandemic.

Personal protective equipment (PPE)

In the context of the COVID-19 pandemic, the World Health Organization (WHO) lists gloves, medical masks, goggles, face shields, gowns, respirators, and aprons as personal protective equipment.

The equipment is intended to be worn by health-care workers and anyone else who may be in close contact with a COVID-19 patient in order to protect themselves and prevent transmission of the virus. 

Presumptive confirmed case

In Canada, a presumptive confirmed case usually means that a person has received a positive test result from a local or provincial laboratory, but they haven’t been confirmed positive by a national body yet.

In Canada, all presumptive COVID-19 test samples are being further tested by National Microbiology Lab in Winnipeg.


Quarantine is a restriction of movement that is typically placed on people who were likely exposed to a contagious disease, such as COVID-19.

Individuals, families, and entire communities can be put into quarantine. They can be mandatory or voluntary, depending on the situation.


In epidemiology, scientists measure the contagiousness of a virus by determining its basic reproduction number, or R0. The number measures how many people, on average, are likely to be infected by one infected person.

For COVID-19, it has an R0 of between two to three, which means the average infected person will likely pass on the virus to two or three people.


SARS-CoV-2 is the name of the novel coronavirus that was first discovered in Wuhan, China, the epicentre of the current outbreak. It is the virus that causes the COVID-19 disease.

The current outbreak has been frequently compared to the SARS (Severe Acute Respiratory Syndrome) epidemic in the mid-2000s. That virus was also a coronavirus and affected the respiratory system.

COVID-19 has also been likened to MERS (Middle East Respiratory Syndrome), another type of coronavirus first identified in 2012.


Individuals can voluntarily put themselves in “self-isolation,” typically at home, if they suspect they have been exposed to a virus, but they’re not showing any symptoms. They’re advised to not have any contact with others during the period of isolation.

For example, if they have had close contact with someone who has tested positive for a disease, they may go into a self-isolation for a period of time to avoid further spread.

Social distancing/physical distancing

Health officials have been recommending “social distancing" or "physical distancing" as a means of limiting transmission of COVID-19. The term essentially means people should stay away from public spaces with large gatherings of people.

It also means individuals should maintain a certain amount of distance from each other. In the case of COVID-19, public health officials advising keeping a two-metre distance from others.

Travel advisory

As cases of COVID-19 continue to grow, governments around the world have put in place travel advisories to alert their citizens of countries or regions where it may be unsafe to visit.

The Canadian government has issued a blanket advisory asking people to avoid non-essential travel outside of the country until further notice.


A virus is considered zoonotic when its origins can be traced to animals. These diseases are known as zoonoses, meaning they are naturally transmissible from vertebrate animals to humans.

It’s believed the virus that causes COVID-19 may have originated in bats and spread through a number of species before it was contracted by humans.