COVID-19 can wreak havoc on your body. Will it cause health problems decades later?

Time and research have shown that the virus has a knack for wreaking havoc on the human body under the right conditions. So what will this mean for the long-term health of millions of people who have been infected – months, years or even decades later?

“There are ‘known’ unknowns, like the rate and duration of long COVID for different individuals,” said Matthew Miller, associate professor at McMaster University’s Center for Immunology Research in Hamilton.

“And then there are ‘unknown’ unknowns, like what might happen in 30 or 50 years.”

Infections related to diabetes, neurological problems

The ability of SARS-CoV-2 to spread throughout the body is largely linked to the spike proteins on its surface, which bind to ACE2 – a protein on the surface of various types of human cells – like a key in a lock. .

This means the virus can reach far beyond the airways, causing inflammation wherever it spreads.

“We have already shown that this virus, even in the acute stage, impacts the brain and our central organs like the heart, pancreas and areas where other viral infections have caused longer-term inflammatory changes that have led to chronic disease,” said Dr. Cory Neudorf, co-lead of the Public Health, Health Systems and Social Policy Impacts pillar of CoVaRR-Net, a team of Canadian researchers who came together for the pandemic.

“I wouldn’t be at all surprised if we see more chronic illnesses from COVID in the years to come.”

SARS-CoV-2 infections have been linked to the onset of diabetes in childhood, for example.

A month of January US Centers for Disease Control and Prevention report showed that young people under the age of 18 were more likely to be newly diagnosed with diabetes a month or more after infection than young people who did not have COVID-19 – and compared to respiratory infections before the pandemic .

“These findings are consistent with previous research demonstrating an association between SARS-CoV-2 infection and diabetes in adults,” the report continues.

Other research has linked even mild cases of COVID-19 to long-term neurological symptoms.

A recent American study, which has not yet been peer-reviewed, involved autopsy results from nine patients and an analysis of impacts on laboratory mice deliberately infected with SARS-CoV-2.

“What we found is that the relatively mild and acute course of SARS-CoV-2 in this mouse model causes significant neuroinflammation,” said lead researcher Michelle Monje, professor of neurology at the Stanford University in California, during an interview with CBC. News.

The team suspects this could be what’s behind the “brain fog” some people describe after a bout of COVID-19, similar to what some people feel after receiving chemotherapy treatment.

Persistent symptoms can be ‘debilitating’

The feeling of post-infection brain fog, along with other lingering effects, is often referred to as long COVID – a well-documented but not yet fully understood phenomenon.

Dr. Angela Cheung, a senior clinical researcher at the University Health Network in Toronto, has spent much of the pandemic working with long-term COVID patients as the co-principal investigator of the Canadian Prospective Cohort Study on COVID-19. Patients’ symptoms, she says, are all over the map – from extreme exhaustion to heart palpitations to trouble sleeping.

“Some people just get a little bit, and they’re like, ‘Oh, my smell hasn’t quite come back,'” she said. “But some people have very debilitating symptoms to the point where they can’t do things, they have to stay in bed all day, they can’t hold down a job.”

Miller, the McMaster researcher, said he was most concerned about these kinds of long-term health impacts that occur soon after infection and seem to persist for long periods of time, “or maybe even for life.

“What I wouldn’t particularly worry about is the likelihood that in 10 or 20 years, tons of people will suffer from major chronic disease related to SARS-CoV-2 infections,” he said. declared.

But even rare diseases, in the context of a global pandemic, could become a huge burden on the healthcare system simply because of the number of people infected at the same time.

Lessons learned from the impacts of the 1918 pandemic

This is a lesson from the 1918 flu pandemic, which sickened more than 500 million people – a third of the world’s population at the time – and had a dramatic impact on global health in the short term, including including tens of millions of deaths.

This global health crisis was also linked to a more modest impact on the health of survivors later in life. A Swedish study, for example, found that exposure to the 1918 strain of influenza before birth, in the womb, may have led to higher rates of health problems and hospitalizations in adulthood.

Typically, later impacts are linked to genetic mutations that can predispose someone to a certain disease, Miller noted.

“An infection compounded by this genetic predisposition could be enough to tip the scales so that this person suffers from a disease that they might not otherwise have experienced,” he said.

WATCH | Doctors scramble to resolve long COVID as patients struggle to recover:

Doctors seek to resolve long COVID as patients fight to recover

Nearly two years into the COVID-19 pandemic, doctors and health experts are searching for a cause and a cure for the long COVID, while patients are simply fighting for their recovery. 6:14

Miller also said that one aspect of this virus, compared to many others, should be somewhat reassuring: our bodies seem to eliminate it.

Unlike HIV, the herpes viruses, or varicella zoster – the virus known to cause chickenpox in children and shingles later in life – SARS-CoV-2 doesn’t seem to stay like a bomb indefinitely. delayed, reducing the risk of serious health outcomes developing decades later.

Still, given all the unknowns around this coronavirus and the short time that has passed since it started spreading among humans, Miller said major questions remain about how infections will affect people. people all the way.

“The vast majority of people who get COVID have a mild infection and survive,” he said. “But that doesn’t take into account what might happen in the future as a result of these infections.”