Masks, flu comparisons and age: Dr. Blondeau talks COVID-19 myths

Clinical microbiologist Dr. Joseph Blondeau says the evidence on mask usage has evolved over the course of the pandemic and increasingly shows face coverings work to slow the spread of COVID-19.

Recently, the U.S. Centers for Disease Control and Prevention updated its website to reflect the latest evidence, including a study that was conducted aboard a naval warship, where sailors were living together in close quarters.

“It has been shown on the warship – it was the USS Theodore Roosevelt — that there was a 70 per cent reduction in COVID-19 transmission on the warship where masks were utilized,” Blondeau said Thursday on Gormley.

He pointed to other studies that had similar findings.

“(There was) as high as 79 per cent reduction in transmission, even within households where there was a positive case, and others in the household were wearing a mask,” he added. “So I think that the story on masks continues to evolve and the underlying message is they work.”

Earlier in the pandemic, the understanding around face coverings was that they prevent an infected person from transmitting the virus to others. But the evidence now shows that even without a perfect fit, they protect the wearer as well, Blondeau said.

Blondeau dispelled some myths people have about the coronavirus. Comparisons to the seasonal flu were among them.

Every year, about a billion people get infected with the flu worldwide, Blondeau said, with between 250,000 and 600,000 people dying. That results in a mortality rate below 0.01 per cent, he continued.

“Now, I don’t mean to belittle that because every death is of course a horrendous outcome of infection,” he said. “But with COVID-19, depending on how you look at the data because it changes a little bit, mortality rates are somewhere in that five to 5.3 per cent rate.

“Depending on populations that are investigated, the rates could be a little bit lower or a little bit higher. But in general, we’re seeing a substantially higher mortality rate. And as a consequence, it is not the same as just seasonal influenza virus.”

Blondeau was asked whether some people are more susceptible than others.

He wasn’t able to point to a study that looked into age as a factor for catching the virus.

“But I think what the data would show is that there are different age groups that handle the virus differently. So for example, we know that patients that are over 70 years of age seem to have a worse outcome,” Blondeau said, adding that comorbidities like heart disease, lung disease or obesity have to be considered as well.

For younger people, he said even while they might experience milder COVID symptoms, there are some patients who develop health problems after.

Some patients develop “auto-antibodies” that attack their own body tissues, while others experience inflammatory or neurological complications.

“So I think what we can assess from the data is that I think everybody is susceptible to infection, but not everybody’s going to handle the virus in the same way,” he said.