Children under the age of five who have been in contact with the coronavirus Covid-19 have a viral load 10 to 100 times greater than adults, according to a study by researchers in Chicago.
The study looked at nasal swabs taken from 145 patients in March and April. The patients were all displaying mild to moderate symptoms of Covid infection, about one week after being infected.
The subjects were divided into three groups: 46 children under five, 51 children aged 5 to 18, and 48 adults. Patients who were more seriously ill were excluded, as were subjects who were asymptomatic.
The viral load discovered in the swabs of children under five was “statistically significant,” the study, published in the journal JAMA Pediatrics, found. In other words, those younger children were carrying more viruses than older children and adults – to the tune of 10 to 100 times more.
The results contradict the view held until now that children are much less likely to become infected, will have milder or no symptoms if they are infected, and are less likely to pass the virus on. That is the reasoning behind the fact that children under 12 are excused from the obligation to wear a face mask.
“We can’t assume that kids aren’t able to spread the virus,” lead researcher Professor Taylor Heald-Sargent of Northwestern University told Fortune magazine.
The authors are careful to point out that the study measured only viral nucleic acid – the equivalent of DNA in viruses – and not infectious virus. But they also point out that other studies have shown that high levels of VNA correlate with the ability to cultivate the Covid virus (officially known as SARS-CoV-2), and that children with higher viral loads are more likely to transmit infection.
“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 paper concludes
“In addition to public health implications, this population will be important for targeting immunization efforts as SARS-CoV-2 vaccines become available.”