Children can effectively spread the coronavirus among themselves, but young adults are the main source of the spread of the coronavirus, according to a study released Wednesday.
The study, based on a giant contact tracing effort involving more than 3 million people in India, shows that most Covid-19 patients do not infect anyone else – researchers found that 70% of those infected did not infect any of their contacts.
Instead, the study found that 8% of patients accounted for 60% of the new infections seen.
The study also contradicts the widely held belief that children are unlikely to catch coronavirus.
“We find the opposite. They are infected in significant numbers, ”study leader Ramanan Laxminarayan from the Center for Disease Dynamics, Economics and Policy in New Delhi, as well as Princeton University, told CNN.
The team wrote in their report, which was published in the journal Science, that “while the role of children in transmission has been debated, we identify a high prevalence of infection among children who were contacts of cases. around their own age. ”
And this despite the closure of schools in India since March, noted Laxminarayan.
The study was based on universal contact tracing efforts undertaken in two large states in southern India.
Authorities have located and tested more than 575,000 people exposed to nearly 85,000 confirmed cases of coronavirus from March to August.
“This is by far the largest contact tracing study in the world,” said Laxminarayan.
“We were surprised to find that only 8% of the primary infected cases were responsible for 60% of the infected contacts,” he said. “It’s an extremely disproportionate effect. Over-spraying was suspected, but not fully documented. ”
Most of the index cases – the first patient in a chain of transmission – were adults between the ages of 20 and 45, according to the team.