Children can carry coronavirus in their noses for up to three weeks, according to a study.
Earlier studies have found the vast majority of children with the virus have mild or no symptoms.
But these findings shed light on the unresolved question of how likely children are to spread the virus to others.
The study emphasises the continuing role of social distancing and good hygiene as children go back to school.
The president of the Royal College of Paediatrics and Child Health, Prof Russell Viner explains there are three separate, but linked questions about children and Covid-19:
Do children get the virus?
While we know for sure that children can catch the virus, Prof Viner says data from antibody blood tests suggest they may be less susceptible to catching it than adults – particularly children under the age of 12.
How severely do they get the virus?
And scientists are very confident that children are less likely to become ill than adults even if they do catch it, with many not showing any symptoms at all.
Do they pass it on to others?
This third question is the one we know least about, and it’s this the study attempts to address.
What does the study say?
The study of 192 children and young adults — newborns to 22-year-olds — found that 49 tested positive for SARS-CoV-2 and another 18 showed symptoms of COVID-19 illness.
What’s more, infected children harbored very high levels of virus within their airways — viral loads exceeding those of very sick adult patients cared for in intensive care units.
That’s important, because the ability of an infected person to transmit SARS-CoV-2 rises with the amount of virus in their system.
“I was surprised by the high levels of virus we found in children of all ages, especially in the first two days of infection,” said study lead author Dr. Lael Yonker, director of the MGH Cystic Fibrosis Center.
“I was not expecting the viral load to be so high. You think of a hospital, and of all of the precautions taken to treat severely ill adults, but the viral loads of these hospitalized patients are significantly lower than a ‘healthy child’ who is walking around with a high SARS-CoV-2 viral load,” she said in a hospital news release. the role of kids in spreading COVID-19 may have been underestimated.
“During this COVID-19 pandemic, we have mainly screened symptomatic subjects, so we have reached the erroneous conclusion that the vast majority of people infected are adults,” he said in the release. “However, our results show that kids are not protected against this virus. We should not discount children as potential spreaders for this virus.”
In the vast majority of cases, children infected with the new coronavirus will not come down with severe illness. The real danger lies in their mingling with more vulnerable adults.
The study was therefore able to give us some new information about children as carriers of the virus, and their potential capacity to be spreading it onwards.
So can we draw a conclusion?
Logic dictates that in both children and adults, people with no or few symptoms – who aren’t coughing and projecting the virus into the air – are likely to be less infectious, and children generally get milder cases of the disease.
But, vast majority of infected children have mild or unrecognised disease, they may play an “important” role in enabling the spread of infection through communities.
The largest study of its kind finds that children can carry exceedingly high amounts of the new coronavirus, even in the absence of symptoms.
Researchers say that could make them ideal “silent spreaders” of COVID-19, throwing the safety of reopening schools into question.
If schools were to reopen fully without necessary precautions, it is likely that children will play a larger role in this pandemic.