SARS-CoV-2 serum prevalence survey at a French day care center suggests low infection rates in very young children

Children aged 5 months to 4 years who participated in day care during the March-May 2020 blockade in France have a low proportion of SARS-CoV-2 antibodies in their blood and are known as serum prevalence. .. This suggests that the virus infection rate is low in this population.

A study assessing the serum prevalence of daycare centers that remained open during the first national blockade in France found that SARS-CoV-2 virus infection rates were as low as 3.7%, with positive cases being domestic adults. It suggests that you are likely to be infected with. In day care. The serum prevalence of day care staff was similar to that of the adult control group who were not exposed to children or COVID-positive patients at work.

This study, which enrolled 327 children between the ages of 5 months and 4 years, was the first to estimate serum prevalence in a preschool environment. Lancet Child & Adolcent Health journal. Many SARS-CoV-2 mutants have emerged since the study was conducted, but these are not included in the data.

Although SARS-CoV-2 has been shown to infect people of all ages, children tend to develop mildly, if any, and rarely require hospitalization. The role of very young children as an asymptomatic SARS-CoV-2 virus spreader remains unclear, and the risk to the community of opening a day care center is unclear.

Serum prevalence data are thought to reflect true infection rates because they indicate levels of antibodies in the blood, whether or not individuals present with COVID-19 symptoms. Therefore, this study may provide important information to policy makers on the closure of day care for very young children during the further wave of the SARS-CoV-2 pandemic, but the authors have other settings and new ideas. It emphasizes that further research on various varieties is needed.

“Our results suggest that day care centers are not the focus of SARS-CoV-2 virus infection and that infants do not spread the virus widely in these environments. These findings are particularly relevant. Parents and staff at the day care center should be reassured. The children included in the study have parents who are key workers and are considered at high risk during the first wave of the epidemic, “said Paris, France. Hôpital Jean-Verdier’s lead author, Dr. Camille Aupiiais, said.

COVID-19 has killed more than 2 million people worldwide and is putting extreme pressure on healthcare systems around the world. Many countries close schools and day care centers to control infection rates. However, these closures come with financial costs and raise concerns about child development and well-being.

During the first French national blockade from March 17th to May 11th, 2020, most day care centers and schools will be closed to take care of the children of important workers, including medical staff and social workers. A small number of diminished daycare centers and schools were closed.

During this time, the French day care center has been working on a small set of cohorts of 6-8 children, each cohort has a dedicated staff, surface disinfection, face masks, staff social distance measurement and other safety. I was advised to follow the protocol. Parents were not allowed to enter the day care center and were instructed to screen their children for COVID-19 symptoms before sending them. Symptomatic children were not allowed to attend the day care center.

The study included 197 day care staff (mean age 40 years). A staff comparator group of 164 adults (mean age 42 years) consists of office workers and lab workers from six hospitals who continued to work during the blockade and were not professionally exposed to very young children or COVID-19 patients. Was there.

Data collection took place from June 4th to July 3rd, 2020, four to eight weeks after the end of the national blockade, at day care centers around the French cities of Paris, Rouen and Annecy. Blood samples were collected from participants (children were stabbed with their fingers) and tested using a fast lateral flow test to detect SARS-CoV-2 antibodies.

In total, 14/327 children, 14/197 day care staff, and 9/164 adult comparators were positive for SARS-CoV-2 antibody. After adjusting the sensitivity and specificity of the test, these values ​​were 3.7%, 6.8% and 5.0%, respectively. Statistically, serum prevalence among day care staff was not significantly different from that observed in the control group.

14 serum-positive children came from 13 day care centers. At the center, which had two sero-positive cases, the children went to different zones of the day care center without mixing. This suggests that there was no child-to-child transmission in these cases.

Contact with cases of adult households with confirmed COVID-19 during the blockade was more frequent in seropositive children than in seronegative children, not in siblings or day care peers. Serum-positive children were significantly more likely to have at least one sero-positive parent (55% vs. 14%).

The 14 sera-positive day care staff came from eight different day care centers, and there were two centers with three sero-positive staff. There was no difference in serum prevalence among staff members who were (or were not) exposed to children with confirmed COVID-19.

“Our results suggest that infants are more likely to be infected with COVID-19 at home rather than at a day care center,” says Dr. Aupieris. “The clinical signs of COVID-19 are not the best indicator of infection, not for testing very young children, and the main criterion should be suspected or confirmed cases of adult household members. Propose. Further research is needed to fully understand the role. The proportion of infants in community infections. “

The authors warn that research is limited and that new variants of SARS-CoV-2 have emerged after the study period. This includes so-called British, Brazilian and South African variants, and it is uncertain whether they are young or not. Children It is more or less susceptible to these new strains. In addition, the day care centers included in the study may not be fully operational during the study period and the results may not be generalized to centers that are operating normally outside the blockade.