Evidence suggests older children biggest vectors, says Blondeau

With the Saskatchewan government set to unveil its plan for returning students to schools, the head of clinical microbiology at Saskatoon’s Royal University Hospital says the most up-to-date evidence points to older children posing the greatest risk of spreading COVID-19.

According to Dr. Joseph Blondeau, children older than 10 seem to transmit the virus in a way that’s similar to adults and there are a few possible reasons.

He said it’s the younger children who lack the receptors that the virus binds to in order to initiate the infection, making them less susceptible.

As well, they have lower lung capacity and thus less capacity to expel respiratory droplets, the main way the virus is spread.

Scientific literature also notes height as a factor, with young children less likely to transmit the virus to adults because they’re not able to interact face to face.

“Clearly at this point in time, it looks like older children and adults are more likely to be the spreaders of the virus and younger children much less so,” Blondeau told Gormley guest host Mike Couros.

“If that data continues to show that particular trend, then it would suggest that older children and adults are more likely to be the vectors that are a concern — and therefore probably where a lot of the efforts in terms of trying to minimize spread need to be spent.”

Blondeau said Sick Kids Hospital has recommended a single metre of physical distance between young children based on those findings.

However, that doesn’t mean kids can’t be infected with COVID-19 and pediatric deaths have been recorded.

Blondeau said authors in scientific journals do not consider their findings to be definitive and they are willing to revise their conclusions should new evidence emerge.

Some measures to prevent the transmission of COVID-19 have proven effective over time — proper distancing, hand hygiene, rigorous cleaning, and cough and sneeze etiquette.

“These basic tools have not changed since this pandemic began and they continue to be, I think, the cornerstone of what we need to be doing in terms of limiting the spread of this virus, whether we’re in a closed environment like a classroom or whether or not we’re out shopping for groceries.” Blondeau said.

Masks are becoming a key part of that toolbox and, in some environments, they can curb the spread by between 30 and 50 per cent. In other settings, they can be as high as 80 per cent effective.

In Blondeau’s view, that’s nothing to sneeze at.

“Thirty to 50 per cent is better than zero per cent,” he said.

The mistake that people want to avoid, he said, is thinking that wearing a mask means they can disregard other guidelines like proper distancing and good hygiene.

Safety in schools and in public will depend on the rules and how easy it is to follow them.

“Unless we all agree that this is an important virus and these measures are important in order to contain it, then we’re going to continue to see viral activity within the population,” Blondeau said.

“We still have an important role as a society to stand up and be counted for and say, ‘I’m going to do my part to limit the spread of this virus.’ I think when we do that and we’re adherent to these very, very important tools, then I think we’re going to be able to control the spread of this virus much better.”