As worries heighten among teachers and parents about rising COVID-19 infections among children, there is one assertion that underpins the back-to-school policies of B.C. health officials: that children are at a “low risk of catching and spreading” the disease.
“Children who have developed COVID-19 have most likely acquired it from adults in the household setting as COVID-19 is more likely to spread between adults than among children,” the BC Center for Disease Control (BCCDC) states online.
This claim is based on research on children and COVID-19 infections gathered around the world prior to September, according to Provincial Health Officer Dr. Bonnie Henry.
“The evidence shows children, particularly under the age of 10, are less likely to shed the virus; much less likely to have severe illness and less likely to pass it on. And that still holds,” Henry asserted to the public October 8.
However, the research surrounding transmissions among children increasingly comes with mixed conclusions, according to Dr. Caroline Colijn, an infectious diseases researcher at Simon Fraser University.
“You might be tempted to ask, ‘How is this going to go well?’” said Colijn, who acknowledges a large body of research indicates children may not be effective transmitters of COVID-19.
However, much research comes from when schools were closed or operating at limited capacity, she notes.
“Of course they were not the index case, right? And then on the flip side there is evidence transmission can happen in schools.”
And so, she said, “I’m not sure I’m convinced. I think the jury is out because a lot of those data are from times when there were not many exposures in school.”
Overall, she continued, “I think it is probably fair to imagine that [children] don’t transmit as much as adults, most of the time. But they also haven’t been exposed as much, so they haven’t had a lot of chances to transmit. So we will see,” said Colijn September 24.
The largest study of COVID-19 contact tracing to date was recently published in Science on September 30 by researchers from top U.S. universities (Princeton, Berkeley and John Hopkins).
Based on the findings from India, “The researchers found that children and young adults were especially key to transmitting the virus in the studied populations,” within the community and in households, stated an online study summary by Princeton.
“Kids are very efficient transmitters in this setting, which is something that hasn’t been firmly established in previous studies,” said Princeton’s lead researcher Raman Laxminarayan.
B.C. Health Minister Adrian Dix said October 13 he stands by the initial research supporting his back-to-school plan.
COVID-19 cases in children are rising in B.C.
While COVID-19 infection and death rates in B.C. remain relatively low compared with the world, in the two to four weeks following school reopenings, infections have spiked among children.
Up to September 24, those aged one day to 19 years accounted for 9% of all confirmed COVID-19 cases, whereas they represented 19% of the province’s population. But between September 25 and October 8 children accounted for 13.8% of all confirmed cases. Ontario shows parallel growth in child infections since September 23, as 15% of all new confirmed COVID-19 cases have been children, up from 7.8% before schools reopened.
Henry told the public October 8 that the higher caseload is a result of a recent four-fold increase of tests performed on children in this timeframe.
Henry stressed the overall data, as opposed to the data following school re-openings: Child infection rates in B.C., she said, are “still less than 10% of cases. They are still underrepresented.”
Furthermore, “What we’re not seeing is schools amplifying transmission in a community,” said Henry October 5.
Meanwhile, the BCCDC has reported no school “outbreaks” to October 12. Initially defined as one transmission event at school, the government’s definition of a school outbreak changed in late September.
“An outbreak in a school setting is when we have ongoing transmission, and we're not clear who has been transmitting to who, and there's widespread transmission in the school or between groups of classes or learning groups. We have not had any outbreaks in our schools yet,” said Henry October 1.
A week prior, Henry told the public, “Unless we start to see transmission in a classroom it would be very unlikely an entire classroom would have to self-isolate.”
To date, Glacier Media is aware of four classrooms that have been told to self-isolate — two at West Vancouver’s Caulfeild elementary on September 24; one at Vancouver’s Elsie Roy elementary on October 3; and one at Surrey’s Rosemary Heights elementary school October 6. All these isolation events have been classified as “exposures.”
Back-to-school plan based on body of research: Henry
The research on children adopted by Henry and the BCCDC helped guide B.C.’s back-to-school plan.
And before school reopened September 10, health officials briefed school trustees on their plan, informing them that schools are not the primary source for community outbreaks.
“In very, very limited cases has a child then transmitted it in the school setting,” Stephanie Higginson, president of the B.C. School Trustees Association, told Glacier Media September 3.
As such, officials amended social distancing standards before school returned. Instead of the two metres people had become accustomed to, social distancing became a “gradient.”
With no apparent reasons to spend more money on extra teachers, support staff and portables, Education Minister Rob Fleming subsequently returned classes at nearly full capacity and with kids in cohorts of up to 60 in elementary school and 120 in high school, for contact-tracing purposes. Meanwhile adults, in the general population were subsequently told by Dix to “stick to six” this fall.
Furthermore, parents are not necessarily deemed close contacts (resulting in isolation protocol) of their infected children who live in the same home – it depends on the circumstances, including age, notes Henry.
Colijn acknowledged face-to-face household interactions likely vary between a less virulent Kindergartener and a more virulent teen.
“So I think that kind of advice varies for those sorts of reasons. That would kind of make sense to me, rather than just saying ‘everyone connected with this child has to isolate immediately.’ But I think those are big assumptions. And especially around the assumptions around asymptomatic children not transmitting. If people didn’t transmit this disease before symptom onset it would be like SARS-1,” said Colijn.
“As we know, if you have a toddler or preschooler, every virus in the kingdom comes to stay at your house. Hopefully not every single one because there’s a bad one out there right now.”
One policy eludes B.C.: Widespread testing
When schools opened, Dix and Fleming compared the B.C. model to Denmark and New Zealand, whose policies reflect similar assumptions made about child transmission.
Both of those countries have similar population sizes and cultural norms. Like B.C., in Denmark and New Zealand, students returned in a gradual manner and they have since returned to full classrooms. As well, the Danes and Kiwis also did not require masks in classrooms.
But while Henry recently touted a daily record 12,052 tests on October 8, Denmark now routinely tests 40,000 to 50,000-plus people per day and has shown similar test positivity rates. As such Denmark has been identifying about three times more cases, of late, although recent hospitalizations and deaths are on par with B.C.
Denmark tests far more children and recommends two tests if they are deemed a close contact of an infected person. If the first test is negative they may return to class but are still tested seven days later, whereas in B.C. a deemed close contact (child or adult) must be isolated for 14 days and no testing is provided if one is non-symptomatic.
Henry has stressed on a number of occasions that tests are a “precious resource” and non-symptomatic testing “uses up a lot of resources.”
She said people are most likely to show symptoms five to seven days after being exposed, however one may still be infectious up to 14 days after exposure – hence the need to isolate for two weeks, irrespective of whether or not one is non-symptomatic.
“Having a negative test during the incubation period doesn’t mean you’re home free. It means you still have to wait to make sure you’re not still developing the virus.” said Henry September 24.
“So our focus here in B.C. is testing people with minimal symptoms, especially adults, and anybody who is part of a public health investigation as part of an outbreak or cluster,” she said.
B.C has run about 639,000 tests to October 12, whereas Denmark has conducted over 4.4 million tests.
New Zealand has taken just over one million tests, despite having one of the lowest community infection rates in the world. After nearly two months of no new positive cases, between May and June, New Zealand saw a spike of a few dozen cases in August, at which point daily tests ramped up to 25,000 per day.
Parent Krista Peters said she was worried enough about potentially spreading the virus to others to get her Caulfeild-attending daughter tested, even though she had no symptoms and was advised not to by health authorities.
Days later she got word her daughter had tested positive.
“Now, that to me, just seems crazy, because how do you know when these kids are actually contagious, if they're asymptomatic the entire time? You just don't know.” Peters told the North Shore News September 28.
Many parents have reported the infections related to Caulfeild on the “North Shore COVID-19” Facebook page and claim the virus has spread among family members, including grandparents.
Transparency complaints compound back-to-school worries
Being told by officials that information on COVID-19 events at school is on a need-to-know basis also sparked criticism of Henry’s policies in the community.
Henry responded by saying the current process of notification is designed to balance health protection and privacy.
A recent study on Canada’s COVID-19 response titled A Time of Fear by Mario Possamai, the senior advisor to Ontario’s SARS Commission, highlights problems with B.C.’s approach: “The most problematic jurisdiction may be British Columbia. Its publicly disclosed data has been incomplete, inconsistent and on occasion, seemingly contradictory.”
Online, health authorities were reporting 71 active exposure events at schools in B.C. on October 12. However, past events have been deleted by the likes of Vancouver Coastal Health authority.
With files from North Shore News