Question Period Note: POST COVID-19 CONDITION

The typical duration of acute COVID-19 illness is two to six weeks. However, some patients have described debilitating symptoms persisting or recurring for weeks or months after acute illness.

Key Messages
• The Government recognizes that some of the Canadians who contracted COVID-19 are facing a long recovery. While our understanding of the long-term health effects of COVID-19 is building, there is still much that is unknown about post COVID-19 condition.
• The Government of Canada is actively working with national and international experts to build the evidence base on post COVID-19 condition to support Canadians experiencing longer-term effects.
• Increasing our understanding of COVID-19, including its longer-term effects, is key to addressing and recovering from the pandemic. To that end, since March 2020, the Government of Canada has invested more than $250 million in critical areas of COVID-19 research.
• The Government of Canada is investing an additional $119 million in COVID-19 research, including funding further studies to better understand post COVID-19 condition.
If pressed on the prevalence of post COVID-19 condition in Canada
• There are currently insufficient data available to determine the percentage of people experiencing post COVID-19 condition in the Canadian population.
• The Public Health Agency of Canada reviewed worldwide studies and found that approximately 50% of adults experienced one or more persistent symptoms more than 12 weeks after diagnosis.
• Studies that follow COVID-19 patients over time, from their initial diagnosis, are underway in Canada. These studies will provide high quality evidence upon which to make decisions.
• The Government of Canada will continue to work with the provinces, territories and other domestic and international partners to monitor and better understand the long-term effects of COVID-19.

The typical duration of acute COVID-19 illness is two to six weeks. However, some patients have described debilitating symptoms persisting or recurring for weeks or months after acute illness. The World Health Organization has developed the first version of a clinical case definition of post COVID-19 condition, which reads as follows:
“Post COVID-19 condition occurs in individuals with a history of probable or confirmed SARS CoV-2 infection, usually 3 months from the onset of COVID-19 with symptoms and that last for at least 2 months and cannot be explained by an alternative diagnosis. Common symptoms include fatigue, shortness of breath, cognitive dysfunction but also others and generally have an impact on everyday functioning. Symptoms may be new onset following initial recovery from an acute COVID-19 episode or persist from the initial illness. Symptoms may also fluctuate or relapse over time.”
A separate definition may be applicable for children.
The range of symptoms reported is broad, and can vary from mild to more severe and debilitating effects that can affect both adults and children, regardless of the severity of their initial COVID-19 symptoms in the acute stage.
It is anticipated that post COVID-19 condition will have a long-term impact on public health in Canada. The Government of Canada is actively monitoring the latest research and information related to the long-term effects and symptoms of COVID-19, as well as engaging with academic experts and policy makers from across the country, and internationally, to help inform public health action.
National Surveillance and Research
Since March 2020, the Canadian Institutes of Health Research (CIHR) has invested approximately $250 million in more than 400 COVID-19 research projects. These projects span everything from diagnostics and potential treatments to public health responses and communication strategies.
The CIHR will support additional research related to variants and other COVID-19 priorities through an ongoing competition that will invest up to $119 million more in COVID-19 research. This includes funding prospective studies that will help increase our understanding of the long-term outcomes of COVID-19. These studies include the Canadian COVID 19 Prospective Cohort Study (CANCOV), which will provide a comprehensive evaluation of early to 1-year outcomes in 2,000 patients with COVID-19 infection and their family caregivers. This study will be conducted in Quebec, Ontario, Alberta and British Columbia.
At the international level, CIHR is a member of the Global Research Collaboration for Infectious Disease Preparedness, an alliance of research funding organizations on a global scale that facilitates rapid and effective research responses to support new, urgent scientific priorities related to COVID-19.
The Public Health Agency of Canada (PHAC) is conducting a systematic review of worldwide studies on the prevalence of post COVID-19 condition, including the prevalence of the various symptoms and sequelae, and the proportion of individuals reporting difficulties in being able to carry out usual activities. The systematic review found that approximately 50% of individuals who were laboratory-confirmed with COVID-19 reported one or more symptoms more than 12 weeks after their initial COVID-19 infection. Many of the included studies had a small sample size and were assessed as having a high risk of bias. PHAC will continue to update this systematic review quarterly to capture results from high-quality studies currently underway.
PHAC is also reviewing the evidence from countries that have implemented large population-based studies with data collection related to Post COVID-19 condition. A recent population-based survey conducted in the UK reported a prevalence of Post COVID-19 condition between 3.0-11.7%. The study was conducted among a sample of over 20,000 study participants 2 years old and over, residing in private households who tested positive for COVID-19. Some potential reasons for a higher prevalence rate observed in the PHAC systematic review compared to the prevalence estimates from the UK population-based survey may include:
• The majority of the population included in the PHAC review were adults, for which preliminary evidence has shown to have a higher prevalence of long term effects due to COVID-19 compared to children.
• The UK survey was conducted in individuals in private households; whereas in the PHAC review, studies did not exclude based on dwelling type;
• Because the UK study did not provide information on study participant characteristics, such as whether they were hospitalized for acute COVID-19 infection, it is possible that the UK study included fewer participants who required hospitalization for their initial COVID-19 infection, unlike in the PHAC review where the majority of participants were hospitalized; and
• The UK prevalence estimates, though based on a very large sample, only included participants from the UK. The PHAC review included participants from multiple countries, across various continents.
The evidence from worldwide and Canadian studies will help to determine the burden and urgency of this public health priority, including what mitigation measures are needed to support the recovery of those experiencing post COVID-19 condition. It will also help with anticipating and planning for longer-term burdens on healthcare systems, patients and their families, and society at large.
PHAC is working with partners such as Statistics Canada, academic organizations and the provinces and territories to assess a number of data sources for surveillance purposes in relation to the long-term effects of COVID-19.
PHAC is also engaging with national and international experts involved in clinical and health services research studies in order to inform public health decision-making, and will be working over the coming months to update the web content that is available to Canadians on this topic.

Key Facts
• Most COVID-19 cases recover from their illness within two to six weeks. However, some people, including those with milder illness, may experience symptoms for weeks or months after their initial diagnosis. These longer-term symptoms are often referred to as “post COVID-19 condition”, “long COVID” and “post-acute sequelae of SARS-CoV-2 infection”. The condition can affect both adults and children. Affected individuals are commonly referred to as COVID-19 long-haulers.