Seroprevalence of SARS-CoV-2 virus infection in employees in the health insurance sector

Introduction. Serological testing for SARS-CoV-2 virus infection is a valuable method of estimating the extent of COVID-19 disease prevalence. The study aims to assess the seroprevalence of SARS-CoV-2 virus infection in a specific group of respondents employed in the health insurance sector, to determine the ratio of symptomatic and asymptomatic cases, as well as to examine susceptibility to COVID-19 in relation to the ABO blood group system. Methods. This research was conducted among 150 randomly selected employees from the health insurance sector of the Republic of Srpska. All respondents completed the survey, voluntary consent to participate, and had a blood sample taken. Serum samples were tested for the presence of SARS-CoV-2 specific IgG antibodies. Results. The seroprevalence of SARS-CoV-2 virus infection was 70.7%. Out of the 100 seropositive respondents, 48% had the presence of a symptom of COVID-19, while 52% had no symptoms of the disease in the period from 1 March 1 2020 until the day of testing. Examining the association between ABO blood group system and seropositivity in our study, we found that the highest seroprevalence of SARS-CoV-2 IgG antibodies among respondents was in blood group B (83.3%), followed by blood group AB (80.0%) and blood group A (75.0%), while the lowest seroprevalence was among respondents with blood group O (54.1%). Conclusion. Among employees in the health insurance sector, SARSCoV-2 seroprevalence of 70.7% was registered. Among respondents with a positive serological result on IgG, 52% were asymptomatic. The seroprevalence of SARS-CoV-2 virus infection is the lowest among subjects with blood group O.