Soroprevalência para SARS-CoV-2 em alunos e profissionais de escolas do município de Campo Grande-MS, de outubro de 2021 a novembro de 2022

Abstract

Introduction: During the COVID-19 pandemic, educational institutions were temporarily closed in an attempt to contain the rapid spread of SARS-CoV-2. With the reopening of schools, it became imperative to understand the role of students and school staff in this transmission process, based on evidence showing a reduction in virus transmission when social contact among school-aged children was minimized during influenza outbreaks. Objectives: To determine the distribution of anti-SARS-CoV-2 seroprevalence among students and school staff in Campo Grande, Mato Grosso do Sul, and to relate it to individual and professional characteristics. Methodology: A seroepidemiological survey was conducted in 20 public and private schools in the urban area of Campo Grande, using a lateral flow rapid test to detect IgM and IgG antibodies against the SARS-CoV-2 nucleocapsid protein, allowing the identification of asymptomatic cases or those with very mild clinical manifestations. Antibodies against this protein are associated only with natural infection by the virus. Testing was carried out in three periods: from October to December 2021, from March to July 2022, and from August to November 2022. Participants included students aged 6 to 17 years, enrolled in elementary to high school, and professionals of varying ages. This study was authorized by CEP-Fiocruz under protocol number 47905721.9.0000.8027. Results: During the first testing period, 162 participants tested positive for IgM and/or IgG anti-N-SARS-CoV-2 antibodies, representing an estimated seroprevalence of 19.6% based on the Bayesian method. In the second and third periods, the numbers increased to 251 (34.6%) and 393 (56.7%), respectively. In 2022, there was a rise in the seroconversion rate compared to 2021, following a surge in cases associated with the Omicron variant. The most commonly reported acute symptoms across all three periods were fever, headache, sore throat, and runny nose. Regarding demographic characteristics, there was no significant difference in weighted seropositivity between sexes, although women accounted for approximately 70% of the study population. No significant differences were observed in seropositivity rates between education levels or professional activities. Conclusion: The results obtained allowed for an analysis of SARS-CoV-2 infection rates and the immunity developed by the studied school population. Additionally, they provided valuable information regarding COVID-19 in children and adolescents. Keywords: COVID-19, serological survey, antibodies, educational institutions, children.