coronavirus type 2 among asymptomatic, RT-PCR-negative members of the Croatian First League

Abstract

The Croatian Football Federation used a novel concept of pre-season systematic evaluation of football players during the
COVID-19 pandemic, with the goal of identifying asymptomatic cases of SARS-CoV-2 infection and stopping their
spread among the team's players. Using a commercial ELISA antibody assay on paired serum samples collected 2 months
apart, this study aimed to determine the prevalence and dynamics of SARS-CoV-2 IgA and IgG antibodies in a cohort of
asymptomatic and SARS-CoV-2 PCR-negative professional football players in the Croatian First Football League.
Methods From May-July of 2020, a group of 305 asymptomatic football players and club staff members underwent
serology testing. Euroimmun ELISA was used in May and July to screen matched blood samples for IgA and IgG (S1 and
NCP) antibodies, and real-time polymerase chain reaction (RT-PCR) was used on three separate occasions to identify
SARS-CoV-2 from nasopharyngeal swabs.