engleski

SARS-CoV-2 seroprevalence in a cohort of asymptomatic, RT-PCR negative Croatian first league football players

Background: During COVID-19 pandemic the Croatian Football Federation has launched a new model of pre- season systematic examination of football players, emphasizing the diagnosis of asymptomatic SARS-CoV-2 infection and preventing further spread among the players during COV. Objectives: The aim of this study was to assess the prevalence and dynamics of SARS- CoV-2 IgA and IgG antibodies in the cohort of asymptomatic and SARS-CoV-2 PCR negative professional football players in the Croatian First Football League by using a commercial ELISA antibody assay in the paired serum samples taken 2 months apart. Methods: Molecular and serology testing was performed from May till July 2020 in a cohort of 305 asymptomatic football players and club staff members. RT-PCR for detection of SARS-CoV-2 was performed in nasopharyngeal swabs on three occasions, and Euroimmun ELISA for detection of IgA and IgG (S1 and NCP) antibodies was tested in paired serum samples in May and July. Results: 20% of participants were reactive in one or two classes of antibodies at baseline and/or follow-up serology testing. IgA reactivity was found in 13.5% baseline sera and 13.8% follow-up sera. IgG to S1 protein was found in 2% of participants at baseline and disappeared at follow- up. IgG to NCP was found in 2 participants at baseline and 8 participants at follow- up. Significant dynamics in the paired sera was found in 5.6% of participants (excluding borderline IgA results) or 10.5% (including IgA borderline results). Conclusion: Various patterns of IgA and IgG reactivity were found in the paired serum samples. Based on serology dynamics we estimate that in 5.9%-10.5% of PCR negative football players asymptomatic exposure to SARS-CoV-2 during pandemics could not be excluded.

SARS-CoV-2 ; COVID-19 ; seroprevalence ; football ; antibodies ; ELISA ; asymptomatic

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