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Why don’t children spread COVID-19 as much as adults? Manitoba experts weigh in

Click to play video: 'COVID-19 in children'
COVID-19 in children
Manitoba research shows children seem to be less infectious when it comes to COVID-19 compared to adults, and they're less likely to be the driving factor in spreading the virus – May 5, 2021

With COVID-19 case numbers once again on the rise and more cases popping up among school-aged children, some infectious disease experts are trying to alleviate the fears and concerns of parents.

“Think of children as vaccinated grandmas,” said paediatric infectious disease specialist Dr. Jared Bullard. “They are unlikely to get sick from it and to spread it as well, and that’s an important way to look at it.”

The latest data published by the province shows there have been 482 cases among school-aged children in Manitoba in the last 14 days.

There have been 7,500 children infected with COVID-19 in the province to date.

“The number of cases of children overall really wasn’t as high as adults, about 20 per cent,” Bullard said. “And that’s not just here in Manitoba, that’s across the whole country.”

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Click to play video: 'FDA set to give Pfizer COVID-19 vaccine emergency use authorization for children 12-15'
FDA set to give Pfizer COVID-19 vaccine emergency use authorization for children 12-15

The proportion of cases involving children that end up severe enough to need hospitalization is still extremely low. Of the 7,500 Manitoba children infected, just 41 have been hospitalized with the virus and one has died.

Bullard said only 0.5 per cent of cases have resulted in hospitalization.

“Kids and the way this virus interact is different,” Bullard said. “So they’re not getting sick and they’re not really getting into hospital and a lot of time they can actually be asymptomatic. They can have the infection, but it’s really not causing them any problems.”

In comparison, Manitoba has had 39,814 total cases and 980 deaths.

Bullard is part of a Manitoba team that has been studying COVID-19 for more than a year. He said even with rising case numbers among those aged 19 and under, they are not the driving factor when it comes to spreading the virus.

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During the outbreaks last summer, the group started looked specifically at how children were infected and impacted.

They collected data and samples from about 175 children under the age of 17 and compared them to information collected from 130 adults. The samples were paired and collected from the same outbreaks within regions for comparison.

“The percentage of samples that grew in (the children’s) culture were about half of what you would see in an adult sample,” he said. “The other important finding was that … they also were growing significantly less virus.”

Children and transmission rates

At the start of the pandemic, Manitoba, like many provinces, went into lockdown, closed schools and sent children home.

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Bullard said the shutdown was based on previous data and the subsequent assumption that children would be the primary drivers of the virus.

“Most of the time, respiratory viruses like influenza, for instance, we see them show up in children first and then within a couple of weeks, we see adult cases start to show up,” he said.

However, with COVID-19 that hasn’t been the case.

Bullard said they are currently finding that children account for less than 10 per cent of transmissions.

He said they are also not the driving factor when it comes to cases associated with schools.

Click to play video: 'St. Vital school outbreak'
St. Vital school outbreak

He pointed to a recent study done in Spain that focused on the reproductive number to highlight the difference in how children and adults were able to transmit the virus.

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He said most of the time when you look at a community, one person infected with COVID-19 will go on to infect two or three others. This was also shown to be true during the Spanish study. But when they compared those numbers to schools and children, there was a drastic difference.

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“What they found was that it was actually closer to 0.3. So that means that you would actually almost have to have several children infected in a school to be able to spread it to even just one person,” he said. “So that rate is quite a bit lower.”

While in-school transmission is low, it can occur and Manitoba schools have been no exception.

Cases and school transmission

Deputy provincial public health officer Dr. Jazz Atwal said the province and schools have been working hard since last year to ensure schools are as safe as possible for students and teachers.

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“The numbers of those individuals who are potentially exposed in the school setting that actually convert to becoming a case are still low and we’re not really seeing them,” he told Global News. “That’s not to say it never happens.”

In St. Vital, Ecole Marie-Anne Gabouray moved to remote learning for two weeks.

It took less than two weeks for one positive case in the Louis Riel School Division elementary school to turn into 22.

But as of right now, the source of that initial infection has not been released.

The city’s largest school division — Winnipeg School Division — has just one school doing remote learning for a few days while public health investigates to determine case causes and if it will need to be extended.

On Tuesday, the province declared two more outbreaks at schools in Winnipeg and moved them to remote learning.

Atwal has been involved in a number of case investigations where transmission was deemed to have happened at school. In many cases, he said, the source of infection has come from a breach of protocol.

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“I’ve been involved with (a case) where we had a teacher who was sitting right next to a student for 20 minutes without a mask on and they became a case because the child was pre-symptomatic and transmitted it to the teacher,” he said.

“Students getting together without masks on and doing things or sharing food items — those are real examples of, yes, transmission did happen to school, but there was a breakdown in the protocol.”

Click to play video: 'COVID-19 in Manitoba schools'
COVID-19 in Manitoba schools

In a number of other cases, investigations have found that an initial case was contracted outside the school through non-compliance with public health orders and then brought into the school.

Atwal said just because children may be in the same cohort at school doesn’t mean they should be getting together outside of the classroom. He said cohorts are designed for the province to be able to contact manage while mitigating risk.

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“We’re not worried about the classroom setting. We’re not worried about even outdoor activities at schools,” he said.

Atwal said the risks happen when choices are made — it could be as small as having children from different households carpool together. If someone within that cohort then becomes a case, investigators are left to try and determine where transmission occurred, which becomes more difficult the more places children interact with friends.

“Was it because they were in the same school or in school together or because they sat and played video games for three hours at someone’s house or they carpool together or in the evening time they watched a movie together? So that’s where we’re seeing that risk in school-age kids,” he said.

Where are cases among youth coming from now?

Throughout the first and second waves of the pandemic, seniors and Canadians living in long-term care facilities were significantly impacted.

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Since vaccines started rolling out in early 2021, those cases have dropped sharply.

But now we are seeing a rise in cases of those under the age of 40 and among younger children.

“We are seeing more cases in children, but there’s an important caveat to that. Remember that we’ve gone out of our way to ensure that the people we know are going to get sick and go in the hospitals have been vaccinated,” Bullard said.

With the elderly and most vulnerable vaccinated, there is now a subsection of younger adults between the ages of 20 and 40, who have higher transmission rates, but have yet to get the shot.

Bullard also noted this population includes parents with younger children and essential workers, who may be bearing the brunt of the third wave.

“They can’t help it,” he said. “They’re going to infect their children when they’re home and so as a result, that’s why we’re seeing more cases in school. But it’s not that the schools themselves are the ones that are propagating that infection.”

Would closing schools slow the spread?

Many experts have spoken out about the numerous benefits to keeping schools open and having children continue to learn in person.

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“We know that children thrive in school,” Bullard said.

Moving children to remote learning can have negative effects on their academic outcomes and their mental health.

Click to play video: 'New research on COVID-19 vaccines and allergic reactions'
New research on COVID-19 vaccines and allergic reactions

For many children, school may be the only safe reprieve they have.

But Bullard said beyond those reasons, schools have ultimately shown to be safe when it comes to the virus.

“The risks for children are pretty small. They’re not going to get sick from it, really. They’re not going to have to go into the hospital. They’re unlikely to spread it between other children or to their parents,” Bullard said.

“So overall, from that perspective, it means that if you shut down a school, you’re not likely to see a huge benefit from that.”

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Questions about COVID-19? Here are some things you need to know:

Symptoms can include fever, cough and difficulty breathing — very similar to a cold or flu. Some people can develop a more severe illness. People most at risk of this include older adults and people with severe chronic medical conditions like heart, lung or kidney disease. If you develop symptoms, contact public health authorities.

To prevent the virus from spreading, experts recommend frequent handwashing and coughing into your sleeve. They also recommend minimizing contact with others, staying home as much as possible and maintaining a distance of two metres from other people if you go out. In situations where you can’t keep a safe distance from others, public health officials recommend the use of a non-medical face mask or covering to prevent spreading the respiratory droplets that can carry the virus. In some provinces and municipalities across the country, masks or face coverings are now mandatory in indoor public spaces.

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For full COVID-19 coverage from Global News, visit our coronavirus page.

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