More than 2,000 summer campers are participating in the Kids Corona study to analyse the transmissibility of COVID-19

As part of the Kids Corona study organised in summer camps, the SJD Barcelona Children's Hospital has collected over 2,000 samples every week from a total of 22 summer schools and sports camps in Barcelona and the metropolitan area. The aim of this study, which has required an unprecedented deployment of resources by the Hospital, is to analyse how COVID-19 is transmitted among groups of children aged between 3 and 15 years and their camp counsellors.

During the weeks that the field study has been carried out, various children and camp counsellors have tested positive during the virus detection tests, with stable cohabitation groups having been placed in quarantine for those who have been in contact with positive or suspected cases. The aim of the samples collected is to analyse the transmission among children and also in relation to the adults looking after them (camp counsellors or teachers) in an environment similar to that of schools.

Under the framework of the Kids Corona platform, the study was carried out in homes where a COVID-19 positive adult had been living, and it demonstrated that the children were infected by a similar percentage to the adults living together, but with an asymptomatic or mild manifestation of the disease. In this case it had not been possible to analyse how the virus was transmitted among the pediatric population who, up until then, had been confined.

For this reason, the hospital decided to launch a new line of research that sought to shed light on one of the greatest conundrums for families and the educational community. "The Kids Corona platform was conceived from social demand", emphasises the Head of Pediatrics and the project's coordinator, Juan José García. "In this case, we wanted to see what happens with children when they are in a setting in which COVID-19 may spread, one which reproduces conditions similar to those that we'll find in schools come September", explains García.

Collection of biological samples and qualitative information

"The volume of participants had to be large, because when the study began, new outbreaks hadn't been detected", explains the Head of the Clinical Research Unit, Joana Claverol. Another selection criteria has been that each participant would stay a minimum of two weeks at the summer camp so that they had relatively prolonged contact with the other children in the stable cohabitation group. Polymerase-chain-reaction (PCR)–based testing of saliva has been performed weekly on all children and adults who have taken part in the summer camps and, at one of the centres (Thau School),  nasopharyngeal PCR-based testing was performed. A follow-up of all cases who tested positive was carried out.

"The nasopharyngeal swab samples were taken because they remain the gold standard for diagnosing COVID-19. In addition to being used to detect the disease, the saliva tests will be analysed to study if antibodies can be detected in the fluid which will help to determine, when a PCR-positive result comes back, whether the child has an active or passive infection, which is something new", adds Iolanda Jordan, Pediatric Research Coordinator for the Kids Corona platform. The study has also included surveys in the summer camps to analyse epidemiological aspects including the number of children who were participating, organisation of the groups, activities inside or outside, etc., which is qualitative information that will contribute to finding out if the disease has more of an impact in some cases than others.

The first study of this type on an international level

"We've done an extensive review of the literature and we haven't found anything similar. We've also contacted international experts who have confirmed that there is still no other study like this one", explains the Head of Pediatrics at SJD Barcelona Children's Hospital. "All of this has been carried out in a record time and has required a great deal of effort by many departments, particularly Nursing and Clinical Research, who have had to postpone other projects to respond to this need", says García.

The Clinical Research Unit at the SJD Barcelona Children's Hospital, led by Joana Claverol, has appointed three people to exclusively work on the design and follow-up of the research at the summer camps, who have worked closely with the 30 members of the nursing team who were deployed to collect the samples at all the summer camps, which has also required a considerable effort in terms of logistics.

The field study has also received the support of five epidemiological investigators from ISGlobal who are working closely with the Hospital. "In addition to this structure, we've had the support of management, the SJD Research Institute, the laboratory teams who have processed and validated the samples on a daily basis, IT and engineering, the administrative team, the people who have been in charge of producing the statistics, etc.", adds Claverol and concludes: "Never before in my life have I had to launch a study of this magnitude in such a short time. This effort has been made possible thanks to the involvement of a large group of people".

In addition to the study carried out in summer camps, the Kids Corona platform has continued to carry out other parallel studies to explain how COVID-19 has manifested in children and how the infection has affected pregnant women and newborns. From this latest study, to date, researchers have been able to analyse 874 pregnant women. The preliminary findings indicate that a total of 14% of pregnant women have antibodies against coronavirus. Pregnant women with the infection in the first trimester (54 women) had milder symptoms, with 70% of women being asymptomatic, and 30% with only mild symptoms. Out of those pregnant women infected during the third trimester (71 women), however, there were fewer asymptomatic cases (52%), with 43.5% showing mild symptoms and 4.5% with pneumonia. These results have been published in the scientific journal The Lancet.