The concentration of coronavirus genetic material detected in the upper respiratory tract of infected children under the age of five is 10 to 100 times higher than that found in older children and adults, according to a US study published this week.
Even if it did not focus on the transmission of the virus, but on its concentration in infected people, this small study, carried out between March 23 and April 27 in a Chicago hospital, complicates the picture concerning the role of children. as vectors in the COVID-19 pandemic.
The researchers, who published their results in the journal JAMA Pediatrics, conducted nasal swab screening tests on 145 patients with mild to moderate COVID-19 a week after the onset of their first symptoms.
The patients were divided into three groups: 46 children under five, 51 children aged 5 to 17, and 48 adults between 18 and 65.
The team observed the presence of the SARS-CoV-2 virus in quantity “10 to 100 times higherIn the airways of young children, compared to older children and adults.
Previous work has shown that the greater the concentration of the virus’s genetic material, the more contagious the virus can become, the study authors point out.
«Therefore, young children can potentially be major contributors to SARS-CoV-2 contagion in the population.According to the team led by Dr. Taylor Heald-Sargent, who specializes in pediatric infectious diseases at Lurie Children’s Hospital in Chicago.
«The usual behaviors of young children and the closed spaces in schools and daycares raise the question of the spread of SARS-CoV-2 in this population as health measures soften.», Conclude the researchers.
From infection to transmission
Little research has been done on the subject to date. This work also needs to be confirmed by other studies. The researchers also point out that few studies have looked at transmission between children and from children to adults.
The portrait that emerges from studies conducted so far is that children develop few symptoms when they have COVID-19 andthey do not transmit the virus.
In an interview with the American network CNN, Dr. Alpana Waghmare, professor of pediatrics at the University of Washington (who was not involved in the study) points out that we also see a higher viral load in children for other infectious diseases of the respiratory tract. The results of this study are therefore somewhat what we expected, she said.
«It is not surprising to find a higher viral load in children. The question now is what does this mean in terms of transmission; it is not yet clear.»
Because there is a paradox: children sick with COVID-19 have high rates of the virus, but little transmission has been observed so far.
«We do not yet have the proof that children will be transmitters of this virus as is the case with influenza, where it is very clear that children who have the flu are the main transmitters.“, Says Dr. Rick Malley, pediatrician at Boston Children’s Hospital, in an interview with the American network NBC.
Some experts suggest that since young children have lower lung capacity than adults, they project their droplets less far than adults when they cough or sneeze. But other experts argue that young children will touch everything and put their hands in their mouths or face often, increasing the chances of transmission, which somewhat contradicts the previous argument.
Others argue that children who have been infected with the coronavirus often have few or no symptoms at all like coughing, which could also reduce the risk of spread. The little ones may also enjoy some cross-protection from exposure to other viruses or past respiratory infections. But these are hypotheses, which must be confirmed by research.
Lead author of the study, Dr. Heald-Sargent, notes that the research that looked at the transmission of the coronavirus from children was done at a time when schools and daycares were closed in most countries, says she interviewed at NBC. Thus, we will have a better idea of the transmission potential when the establishments reopen in the fall.
Recently, a large South Korean study has shown that young people aged 10 to 19 transmit COVID-19 just as effectively as adults, another element to be taken into account by authorities for the return to school this fall.
Gallery: 10 Causes of Dementia You Can Treat Before It’s Too Late (Health Pleasures)