Only a fraction of children show Covid-19 symptoms: Study

According to a study by the researchers at the University of Alberta, over one-third of Covid-19 positive kids are asymptomatic, indicating that young people diagnosed with the infection represent only a fraction of infected people.

For the study, Finlay McAlister, Professor of Medicine, Faculty of Medicine & Dentistry, University of Alberta, and his team analysed results for 2,463 Covid-19 positive children. These children were tested during the first wave of the pandemic--March to September.

The study noted that 1,987 children had a positive test result for Covid-19 and 476 were negative. Of positive children, 714 (35.9 per cent) were asymptomatic.

McAlister said: "It speaks to the school safety programs. We can do all the Covid-19 questionnaires we want, but if one-third of the kids are asymptomatic, the answer is going to be no to all the questions--yet they're still infected."

He added, "As far as we know, kids are less likely to spread disease than adults, but the risk is not zero. Presumably asymptomatic spreaders are less contagious than the person sitting nearby who is sneezing all over you, but we don't know that for sure."

The researchers further observed that cough, runny nose, and sore throat were the the most common symptoms among children with virus. These symptoms were present in 25, 19, and 16 per cent of cases respectively. Surprisingly, they were actually slightly more common among those with negative Covid-19 test results, and therefore not predictive of a positive test.

"Of course, kids are at risk of contracting many different viruses, so the Covid-specific symptoms are actually more things like loss of taste and smell, headache, fever, and nausea and vomiting, not runny nose, a cough, and sore throat," he said.

Further research

McAlister noted that his team is now working to put forth a paper that proves sore throats and runny noses aren't reliable signs of Covid-19 in adults either, although the vast majority of adults (84 per cent) do show symptoms.

"Sore throat and runny nose means you've got some kind of upper respiratory tract infection, but fever, headache, and loss of taste or smell are the big ones for indicating that one may have Covid-19 rather than another viral upper respiratory tract infection," he said.

McAlister added that if people have any symptoms at all, they should stay home and get tested. He recommended that those who feel well should still be doing everything they can to stay safe--wearing a protective mask, frequent handwashing, keeping distance, and avoiding meeting indoors.

The findings of the study were reported in the journal News Medical and Life Sciences.