Seroprevalance of anti-SARS-CoV-2 antibodies in the IgG class in hospitalized children in the north-eastern part of Poland in 2021.

Abstract

In children, SARS-CoV-2 infection may manifest with symptoms of fever, cough, muscle pain, diarrhea or waste smell and taste. However, in most cases it is mild or asymptomatic. Determination of the level of anti-SARS CoV-2 IgG antibodies in children enables to assess retrospectively the incidence of the SARS-CoV-2 infection among children. The aim of the research was to analyze the results of anti-SARS-CoV-2 antibodies in the IgG class contained in children hospitalized in north-eastern Poland in 2021. The material for the study was venous blood collected once from children hospitalized in Children's University Hospital in Białystok in 2021. The results obtained from 615 children aged from 1 month to 11 years were analyzed. Determination of the level of antibodies was performed using the automated SARS-COV-2 IgG II test on the VIDAS® analyzer. The analysis of the results of the anti-SARS-CoV-2 IgG value showed that half of children (52%, n=319) had contact with SARS-CoV-2 virus of which approximately 15% (n=47) had documented infection with this virus. There was no difference in the frequency of infections among boys and girls, antibodies were detected in 51% and 53%, respectively. The highest percentage of positive results was observed in children aged 7 to 10 years, 62% (91/147). The least children with a positive result were in the group below 1 year of age, 24% (4/17). High values of the antibody index (>15.00) were most often found among younger children, aged 1-2 years. The presented results showed that infection with the SARS-CoV-2 virus does not depend on the sex of children but the value of anti-SARS-CoV-2 IgG antibodies decreased with the age of the child.