Seroprevalence of antibodies against SARS-CoV-2 among workers in a national research institute and hospital in Central Japan

Abstract

To achieve effective prevention and control strategies for COVID-19, regular survey of seroprevalence of antibodies against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is essential. Using four serological tests, we examined the residual sera collected in an annual medical checkup of the staff members of the National Center for Geriatrics and Gerontology in Aichi Prefecture, Central Japan in June 2020. Of the 631 samples, two were positive for anti-SARS-CoV-2 antibodies in at least two tests, showing a seroprevalence of 0.32%. Four subjects showed positive results in only one test. All individuals were asymptomatic and had not been in close contact with patients diagnosed with COVID-19. Multiple antibody tests could be used to assess the prevalence of SARS-CoV-2 infection including individuals without COVID-19 symptoms.