The boy was part of a group of cases linked to Steve Walsh, the Hove-based businessman who became the first Briton to test the coronavirus after attending a sales conference in Singapore in January.
Walsh unintentionally transmitted the infection when he joined 10 British adults and a family of five in a chalet at the Contamines-Montjoie ski resort in Haute-Savoie after flying from London.
Most chalet customers have contracted the virus, but a public health investigation from France found that the nine-year-old boy did not pass it on to his siblings or anyone else, even though he entered in contact with 172 people, all quarantined as a precaution, and having lessons in three separate ski schools.
An investigation report published in Clinical Infectious Diseases describes how the tests revealed that the boy was infected with Sars-Cov-2, the virus that causes Covid-19, as well as the flu and a cold virus. While his two siblings got the latest infections, neither got the coronavirus.
“One child, co-infected with other respiratory viruses, attended three schools when he was symptomatic, but did not transmit the virus, suggesting a potentially different dynamics of transmission in children,” said Kostas Danis, epidemiologist at Public Health France at the French press agency AFP.
The boy had only mild symptoms and, when tested, had barely detectable virus levels. The low level of infection is believed to explain why he did not infect other people.
Researchers believe that children usually have only mild symptoms, so they can transmit the virus much less than infected adults. “Children may not be a major source of transmission for this new virus,” they write.
The reasons why children generally escape the worst of the virus are not well understood, but many scientists suspect that their immune response is somehow able to clear infections faster than the elderly, who tend to be affected much more severely by the disease.
The report comes after UCL researchers concluded this month that school closings are likely to have little effect on the spread of the virus, and that this should be weighed against the social costs. and deep economic. Dozens of countries have closed their schools to slow the transmission of the coronavirus, although restrictions have been introduced to avoid social gatherings around schools and limit the spread of the virus within them.
The role of children in the spread of the virus remains one of the main mysteries of the coronavirus pandemic and the question of whether those who develop little or no symptoms are carriers. While the proportion of children with serious illness is small compared to that of the elderly, some have become seriously ill and died from the infection.
“A better understanding of who is responsible for transmission and when the disease progresses is a very important part of the puzzle and we still don’t really have much knowledge,” said Professor Jonathan Ball, virologist at the University of Nottingham. “I keep hearing about a major asymptomatic infection, such as US Navy personnel, but I still have no real idea how important it is in terms of spread.”