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Long COVID - How Common Is It?

Oct 22, 2022
Eleanor Stein, MD FRCP(C)
Long COVID - How Common Is It?
10:25
 

How Many Canadians Have Long COVID?

Now that COVID-19 is less often in the news, you might be wondering how many people are still getting infected, how ill they become and whether they are getting long COVID. On October 17th a report was published by Statistics Canada in collaboration with the Public Health Agency of Canada on a representative sample of Canadians with Long COVID. Although it is our most comprehensive data to date, it doesn’t include everyone. The sample excludes people under the age of 18, residents of Canada’s three Northern territories, those living on indigenous reserves, soldiers in the Armed Forces, penitentiary inmates and inhabitants of some remote communities.

The data are shocking. Up until the end of May 2022, 32% of Canadians over the age of 18 reported a positive COVID test and another 8% suspected but couldn’t prove they had had COVID 19. This adds up to 40% of Canadians. The authors add that this number is almost certainly an underestimate, because so few tests have been offered over the past year.

How severe is COVID 19 Currently?

Of the people who had or believed they had COVID 19, the severity of symptoms and the impact on daily life is shown in the table below. It is important to note that more women than men reported moderate to severe symptoms.

 Severity of COVID 19 Infection

No Symptoms

 

5%

Mild Symptoms

Did not affect daily life

34%

Moderate symptoms

Had some effect on daily life

44%

Severe symptoms

Had a significant effect on daily life

17%

 

What Symptoms Do People with Acute COVID 19 Report?

The symptoms most commonly experienced by those who were ill include:

  • fever
  • dry cough
  • fatigue
  • loss of taste or smell
  • sore throat
  • headache
  • muscle or joint pain
  • shortness of breath
  • pain or pressure in the chest and
  • anxiety or depression

These symptoms are flulike with the addition of chest and breathing problems. No hint here of the progression to Long COVID.


How Common Is Long COVID?

Of those who had or thought they had COVID 19, 14.8% were still feeling unwell three or more months after their initial infection. This is the most common definition for Long COVID.

So now for the big reveal.

Canada’s population in 2022 = 38.5 million

40% of these have gotten COVID = 15.4 million

14.8% of these developed Long COVID = 2.3 million

More women (18%) than men (12%) reported prolonged symptoms. People who had severe symptoms when they first got COVID were more likely to develop Long COVID.

A surprising finding is that almost 1/3 of people with Long COVID had fully recovered from their initial symptoms and then the symptoms returned. Men are more likely than women to have symptoms which return after apparent recovery.

 

What Are the Most Common Symptoms of Long COVID?

The most common symptoms of Long COVID in this Canadian study are a mix of symptoms experienced by people with ME/CFS such as fatigue and brain fog and the respiratory symptoms such as cough and shortness of breath caused by the COVID infection.

 Symptoms of long COVID

 

Fatigue

72%

Cough

39%

Shortness of breath

38%

Brain fog

33%

 

This list of symptoms is much shorter than the exhaustive list published by the patient led research collaborative Body Politic in conjunction with researchers at University College London, the Weill Cornell medical Centre and the Oregon health and science University. In this collaborative paper published in mid-2021, post-exertional malaise was the second most common symptom. PEM was defined as relapses triggered by exercise, physical or mental activity and stress. 45% of people in this sample of volunteers had reduced their work hours due to their symptoms and 22% were not able to work at all.

 

What About the Omicron Variant?

There has been a lot of speculation about how the emergence of the Omicron variant will impact Long COVID. The Omicron variant became the dominant strain just under a year ago in December 2021. This was also the time when universal testing was discontinued. This means that it is harder to know exactly what is going on. It appears that being infected with Omicron has a better prognosis. Only 10.5% of people developing COVID since December 2021 report symptoms of long COVID. This is great news.

 

What Is my Recommendation for Vaccination?

Before the introduction of the bivalent vaccines, there was a decrease in effectiveness of the mRNA vaccines against the omicron variant though they still protected against severe outcomes. According to the Centers for Disease Control in the US, the new bivalent vaccines offer over 80% protection against the most severe outcomes. In general, the effectiveness of the vaccine lasts for 7 to 8 months after two doses and there is evidence that the third and fourth doses prolong the benefit. For example, in a study of healthcare workers in Israel, among those who had received four doses of vaccine, only 7% became infected compared with 20% of those who received only three doses of the vaccine.

Given the lack of mention in the news these days, you might be wondering if vaccination is still necessary. In Alberta, there are fewer people hospitalized and far fewer people in ICU during this omicron wave. However, just in my immediate circle, people who have been infected with Omicron have told me that it was not a pleasant experience and they wouldn’t recommend it. And people are still dying, predominantly the elderly and those with weakened immune systems or other risk factors such as obesity or heart/lung disease.

To maintain herd immunity and prevent severe outcomes, I recommend continuing vaccinations for the foreseeable future. This is especially true if you are at high risk of a more severe outcome or if you live with someone at risk of a severe outcome. A Swedish study showed that if even one family member is vaccinated, the risk of others in the family contracting COVID is lower. The more people vaccinated, the lower the risk to vulnerable family members.

However, if the COVID variants continue to become less lethal, the decision about vaccination becomes less clear. We are quickly approaching the point where vaccination may become more of a choice than a public health imperative. People will increasingly make their decision based on personal risk and the risk of the people in their immediate circle. Let’s hope we are on the tail end of this experience.