As provinces across the country announce plans to re-open schools in the fall, a new study suggests children younger than age five may have 10 to 100 times greater levels of the coronavirus in the upper respiratory tract compared to older children and adults.
In the small study, published Thursday in JAMA Pediatrics, researchers analyzed swabs taken from 145 people between March 23 and April 2 at drive-in clinic in Chicago.
Patients were grouped by age: 46 children younger than five years old; 51 children aged five to 17 years; and 48 adults aged 18 to 65 years. The participants’ race or sex and whether they had underlying conditions were not identified.
The researchers only included children and adults who had mild to moderate symptoms and if they were able to gather details about when symptoms first began. People who didn’t have symptoms and who did not remember when they started to feel sick were left out of the study.
Researchers found “a 10-fold to100-fold greater amount of SARS-CoV-2 in the upper respiratory tract of young children.”
“Young children can potentially be important drivers of SARS-CoV-2 spread in the general population, as has been demonstrated with respiratory syncytial virus, where children with high viral loads are more likely to transmit,” say the authors, led by Taylor Heald-Sargent of the Ann & Robert H. Lurie Children’s Hospital.
“Behavioral habits of young children and close quarters in school and day care settings raise concern for SARS-CoV-2 amplification in this population as public health restrictions are eased.”
The authors also said young children will be an important target for immunization efforts of COVID-19 when vaccines become available.
Meanwhile, an analysis by Canadian researchers released earlier this week found that young children — mainly those under the age of 10 — are less likely than teenagers and adults to spread COVID-19.
The analysis looked at 33 studies across 16 countries and found fewer so-called “superspreader events” involving children.
The review, released Tuesday, was compiled by the National Collaborating Centre for Methods and Tools (NCCMT), which was set up in response to the 2003 SARS outbreak and funded by the Public Health Agency of Canada.
“What we see consistently across studies is that children are not likely to be major sources of COVID-19 transmission,” Sarah Neil-Sztramko, an assistant professor with the NCCMT and McMaster’s department of health research told Global News.
One of the studies from Israel that was reviewed found a serious outbreak at a Jerusalem high school that occurred 10 days after schools fully reopened on May 18. The outbreak at the Grade 7-to-12 school infected nearly 153 students and 25 staff members.
Isaac Bogoch, an infectious diseases physician at Toronto General Hospital, said the bottom line from all these studies is that, yes, children can get infected with COVID-19 and can transmit the virus.
“To what extent they can transmit the infection is currently being debated,” Bogoch said. “But the fact is, anyone of any age can get this infection. Anyone of any age can transmit this infection.”
“We’re putting hundreds of kids together under one roof. If infection control plans are not implemented properly, there is certainly the potential to amplify this infection,” he said.
As provinces roll out plans for how to safely return students to the classroom amid the ongoing pandemic, Bogoch said most announcements so far have been fairly good and contain the fundamental public health principals of wearing masks or physical distancing.
The key, he said, is whether those plans are actually carried out in September.
“You can have really good plans and really good blueprints at the provincial level. But the rubber hits the road at the school,” he said. “If it’s not being implemented well in the school setting, then there’s going to be problems.”
— With a file from Don Mitchell
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