Threat of long-term symptoms increases with multiple COVID-19 infections: Statistics Canada report

A new Statistics Canada report suggests one in nine Canadian adults have experienced long-term symptoms from a COVID-19 infection, and the threat of long-term symptoms increases with multiple infections. 

“The increased rate at which long-term symptoms occur in those with COVID-19 infections is an observed phenomenon that sets the illness apart from other respiratory viruses, such as the flu,” the report said.

“This may be related to the fact that COVID-19 affects a wide range of body systems, not limited to the respiratory system, and has been documented to be able to cause organ damage in infected individuals.”

Released Friday, the joint Statistics Canada-Public Health Agency of Canada report is titled Experiences of Canadians with long-term symptoms following COVID-19. 

Intended to provide updated estimates on COVID-19 infections and reinfections among adults and to describe the nature of symptoms, it used data from a follow-up questionnaire to the 2023 Canadian COVID-19 Antibody and Health Survey. Those results were compared to a previous survey conducted in 2022 and reported here. 

The new study identified long-term symptoms as “the presence of symptoms three or more months after a confirmed or suspected COVID-19 infection that could not be explained by anything else.”

It found that Canadians who reported two COVID-19 infections (25.4%) were 1.7 times more likely to report long-term symptoms than those who’d had only one infection (14.6%). Those with three or more infections (37.9%) were 2.6 times more likely to suffer prolonged symptoms. 

As of June 2023, an estimated 2.1 million Canadian adults were experiencing long-term symptoms as the result of a COVID-19 infection. Among Canadians who reported long-term symptoms, 58.2% continue to experience them compared to the 41.8% who reported them resolved. 

‘Best to avoid it altogether’

Canada’s Chief Science Advisor Dr. Mona Nemer cited the new report on her Twitter account Sunday. 

“Even mild cases of SARS-CoV-2 infection are at risk of becoming long covid, and these results suggest the threat increases with multiple infections,” Nemer wrote.

“These results are corroborated by scientific studies, including this one by @zalaly and team. Overcoming it once doesn’t necessarily protect you from subsequent cases that are worse. Best to avoid it altogether.”

The new report said despite the May, 2023 declaration from the World Health Organization (WHO) that COVID-19 was no longer an emergency of international concern, it continues to cause “significant concern” for the health of the Canadian population and the wider international community. 

Accumulating research indicates that COVID-19 is associated with long-term effects on health including the presence of symptoms months or years after the initial infection.

For some, these long-term symptoms cause significant hardship that affects their health and ability to contribute to society.

‘No consensus definition of the condition nor for its diagnosis’

In May of this year, Nemer’s office issued a document titled Post-COVID-19 Condition in Canada: What we know, what we don’t know, and a framework for action. 

That report said people suffering with Post-COVID-19 condition, also called long-COVID, experience a broad range of symptoms and conditions. They can range from high blood pressure and heart arrhythmia to “broad or medically undefined symptoms such as cognitive problems (“brain fog”), exhaustion, chronic pain and fatigue.”

That May report noted that there’s “no consensus definition of the condition nor for its diagnosis.” There are also few, if any, clinical practice guidelines available. 

“Individuals suffering from the condition receive the standard of care for medically defined symptoms but for the many who suffer from other symptoms, little other than rehabilitation therapy is presently offered,” that report said.

Fatigue, brain fog, shortness of breath among commonly reported symptoms

The national study released Friday found that despite the wide range of reported long-term symptoms, some do appear to be more common. The most frequently experienced are fatigue (65.5%), brain fog (39%), and shortness of breath (28%). The report noted these more common long-term symptoms have also been reported internationally. 

It also found that since the emergence of Omicron, people with long-term symptoms were more likely to report feeling worse after physical or mental activity and to experience coughing and fatigue. Unlike in the earlier days of the pandemic, people are also less likely to report headache or loss of smell or taste.

The report also noted long-term symptoms can develop beyond three months, or may even return after an initial recovery. 

Among individuals who reported not experiencing symptoms three months or longer after a COVID-19 infection in the summer of 2022, 11.1% have since reported developing long-term symptoms after that same infection that could not be explained by anything else.

Long-term symptoms range from mild to debilitating

As reported here last May, 80% of respondents to a national survey said long-COVID had negatively impacted their brain health. More than 70% said they’d taken leave from work as a result of living with long-COVID, sometimes for periods longer than a year. Some were forced to leave the workforce entirely. More than 60% of that survey’s respondents were between the ages of 40 and 59.

The latest study found that the more than one in five Canadians dealing with long-term symptoms while employed or in school had missed, on average, 24 days of work or school.

The report described the effects of long-term symptoms as ranging from mild to debilitating. About 70% experienced them daily or almost daily when symptoms were at their worst, while 21.7% said they were “often or always” limited by their symptoms in their daily activities. 

Only one in eight received adequate care

As of June 2023, 46.9% of Canadian adults with long-term symptoms had consulted a health care provider or service about their post-COVID symptoms. 

However, of those who sought help, only one in eight felt they had received adequate care. Only 12.5% of Canadian adults who needed care reported receiving treatment, services, or support for all their symptoms. Among those still experiencing long-term symptoms as of June 2023, only 5.7% had received a post COVID-19 condition diagnosis. 

Of the estimated 2.1 million Canadian adults who – as of June 2023 – continue to experience long-term symptoms after a COVID-19 infection, almost 80% had been dealing with them for six months or longer.

The study’s conclusion noted that since two in five affected Canadian adults were accessing health care for long-term COVID-19 symptoms, “awareness of the condition and evidence-based methods for diagnosing, treating, and managing it are important.”

However, this study found that a substantial number of adults with long-term symptoms experienced difficulties accessing healthcare for their symptoms, and 2 in 3 who needed healthcare services reported not receiving treatment, services or support for any of their symptoms. 

Considering these findings, protection against COVID-19 infections including reinfections and the development of long-term symptoms is paramount.