Coronavirus disease (COVID-19): For health professionals

On this page

What health professionals need to know

Health professionals in Canada have a critical role to play in identifying, reporting and managing potential cases of COVID-19.

COVID-19 is the disease caused by SARS-CoV-2 coronavirus, a new virus that was first recognized in December 2019. Genetic sequencing of the virus suggests that it is a betacoronavirus closely linked to the SARS virus. Coronaviruses are a large family of viruses. Some can infect animals, and some can infect humans.

The World Health Organization (WHO) declared COVID-19 a global pandemic in March 2020.

As we learn more about the virus, clinicians must remind Canadians to keep doing their part to prevent the spread of COVID-19. This includes following public health precautions, such as:

The WHO is actively monitoring the situation and has issued:

We are monitoring the COVID-19 situation closely, both in Canada and globally, and providing regular updates.

Causative agents

The coronavirus has been named SARS CoV-2.

Signs and symptoms

We have compiled a clinician guide for COVID-19. Based on scientific evidence, and informed by expert opinion, the guide outlines:

This guidance is subject to change as new information emerges.

Clinical presentation and symptoms of COVID-19 vary in frequency and severity. Symptoms can take up to 14 days to appear after exposure to the virus.

People with COVID-19 may have few or no symptoms. Symptoms are often similar to other illnesses, particularly other respiratory viruses such as rhinovirus or influenza, amongst others. People can transmit the virus before they develop symptoms (pre-symptomatic transmission). Some infected people never develop symptoms, but can still transmit the virus (asymptomatic transmission). That is why everyone, even those who feel well, should follow measures to prevent the spread of COVID-19.

The true frequency of symptoms associated with COVID-19 is unknown. People with more severe symptoms may be overrepresented in published reports. Symptoms may also differ across care settings. More symptoms may develop as the disease progresses.

There is no validated list of symptoms with high specificity or sensitivity for the diagnosis of COVID-19. Clinical diagnosis should therefore always be confirmed by testing.

Encourage patients to seek medical consultation if they have new or worsening symptoms.


The main mode of transmission for COVID-19 is person-to-person spread via respiratory droplets. The virus is contained in the droplets of an infected person. When the infected person coughs, sneezes, talks or breathes, their droplets can reach the mucous membrane of another person and infect them.

Infection can also occur when a person touches an infected surface and then touches their eyes, nose or mouth. We do not fully understand the contribution of surfaces or objects (also called fomites) in COVID-19 transmission.

The time period in which an individual with COVID-19 is infectious remains uncertain.

Incubation period

The incubation period ranges from 1 to 14 days. The median is 5 to 6 days between exposure and symptom onset. Most people (97.5%) develop symptoms within 11.5 days of exposure.


There is emerging evidence of human re-infection with SARS-CoV-2. This has been documented by individuals confirmed to have been infected by different strains of the virus. Further research is required to fully comprehend the relationship between positive antibody tests and any protection against re-infection.

Currently, we do not know:

Early research appears to indicate that neutralizing antibody levels can decrease following recovery from COVID-19. As serological testing for antibodies expands, the results may provide insight into re-infection and duration of immunity.

The Government of Canada launched the COVID-19 Immunity Task Force in April 2020. The task force is focused on tracking the spread of the virus in the general population and shedding light on immune responses to SARS-CoV-2 in a diversity of:

Risk factors for severe disease

Coronaviruses can result in severe illness for some people in our communities. Those who are at risk of developing more severe disease or outcomes from COVID-19 are people:

Learn more about disease severity and risk factors for severe disease in our clinician guide for health professionals.

Infection prevention and control

We have developed infection prevention and control guidance and strategies to prevent or limit COVID-19 transmission in health care settings, including:

There is an unprecedented demand and urgent need for products to help limit the spread of COVID-19. As a temporary measure, we are speeding up the authorization processes for personal protective equipment (PPE).

We are also allowing certain medical devices to be imported and sold that may not fully meet Canadian regulatory requirements. However, these devices are manufactured to comparable standards.

Learn more about strategies to address PPE shortages, including the reprocessing of N95 respirators.

Training for contact tracing

Register for our free training courses on contact tracing. You will need to make an account before being able to register. Our series of courses supplement local training and onboarding. They are not a requirement to conducting work in your jurisdiction. Health professionals must follow local/regional policies and procedures for contract tracing.


Our National Microbiology Laboratory (NML) helped develop and verify the laboratory tests used to identify COVID-19. NML has worked closely with provinces and territories through the Canadian Public Health Laboratory Network to advance testing capacity in Canada. Additionally, NML scientists continue to investigate novel technologies to detect COVID-19, which can potentially enhance access to testing and increase ease of collection.

Health Canada regulates the sale and import of commercial testing devices relating to COVID-19. The majority of submissions received are for 2 types of commercial testing devices:

  1. nucleic acid-based testing
  2. serology-based testing

Consult the list of testing devices that have been authorized to date for use related to COVID-19.

Only testing devices authorized by Health Canada can be imported or sold in Canada. Unauthorized tests may not produce accurate results, leading to potential misdiagnosis. COVID-19 tests are confirmed to be well supported by evidence indicating they will provide accurate and reliable results.


We do not accept reports from the public or individual health care providers. Reporting is completed by provincial or territorial health authorities.

The Public Health Agency of Canada (PHAC) collaborates with provincial and territorial public health partners to collect information on COVID-19 cases in Canada. A detailed epidemiologic summary is available.

Recommendations to public health care professionals

Treatment and vaccines

We are tracking all potential drugs and vaccines in development in Canada and abroad. To help expedite the development and availability of treatments to prevent and treat COVID-19, we are working with:

Among hospitalized patients who have COVID-19 and require supplemental oxygen or mechanical ventilation, clinicians should strongly consider:

On July 27, 2020, Health Canada authorized with conditions the use of Veklury (remdesivir) to treat COVID-19 in adults and youth (12 years and older weighing at least 40 kg) with pneumonia requiring supplemental oxygen. Remdesivir is the first drug authorized to treat patients with severe symptoms of COVID-19 who have been hospitalized.

There are currently no vaccines authorized for COVID-19 in Canada.

As of October 2020, Health Canada began receiving submissions for approval under the drug authorization Interim Order for COVID-19. Health Canada will carefully review all of the data provided. Before any new vaccine or treatment is made available to Canadians, it must be shown to be safe, effective and of high quality.

Products that may ease symptoms such as fever and cough may be used to treat patients with COVID-19.

Together with a network of clinical experts, we have developed guidance for the clinical management of COVID-19 patients. This guidance is not meant to replace clinical judgment or specialist consultation.

Refer to the interim guidance on:

For more information on treatment under development, refer to the authorized clinical trials.


Refer to our guidance for health professionals for clinical guidance on COVID-19, including:

Related links

What COVID-19 information do you need?

Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: