https://english.elpais.com/society/2020-08-26/major-coronavirus-study-in-spanish-summer-camps-shows-low-transmission-among-children.html
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Children and adolescents who took part in 22 summer camps in the Barcelona area in recent months have been found to have a capacity to transmit the coronavirus that is up to six times lower than that of the general population.
That is the preliminary conclusion of the biggest study so far carried out about the transmission dynamics of SARS-CoV-2 among minors. The research was carried out by a team from the Sant Joan de Du children's hospital in the Catalan capital. The authors of the study chose summer camps on the basis that they are "environments that are comparable with, or similar to, those of schools."
For five weeks, the study tracked "more than 1,900 people, including children and monitors, at 22 summer schools in the Barcelona area, in an urban environment," explained Juanjo Garca, the head of pediatrics at the hospital. "Every week a group of hospital personnel would travel to the camp and take saliva samples for a PCR test," he added. This type of screening was one of the novelties of the study, given that it is usually done using blood samples.
"For the five weeks that the investigation lasted, we were able to detect 39 newly appeared index cases," of which 30 were found in children, Iolanda Jordan, the head researcher, explained. "These children had 253 contacts, who were boys and girls from their respective cohabitation groups. From these, there were only 12 contagions, which is 4.7% and an R reproduction rate of 0.3. This is a low R number, six times lower than the one that we have found among the general population, which ranges from 1.7 to 2," Jordan added, in reference to the same neighborhoods in which the summer camps were taking place.
Another significant discovery, Jordan continued, is that "children under the age of 12 have the same transmission capacity as those aged 13 to 17."
