Seroprevalence of SARS‐CoV‐2 in Utsunomiya City, Greater Tokyo, after the first pandemic in 2020

BackgroundA seroepidemiological study was conducted on a random sample of households in Utsunomiya City, Tochigi Prefecture, Greater Tokyo, Japan, to assess the seroprevalence of SARS‐CoV‐2.MethodsThe level of IgG antibodies in the blood of the recruited subjects was assessed using chemiluminescence immunoassay analysis. In addition, the population‐based prevalence of SARS‐CoV‐2 was estimated.ResultsThree positive afebrile cases were confirmed. The estimated unweighted prevalence and weighted prevalence of SARS‐CoV‐2 infection were 0.40% and 1.23%, respectively.ConclusionsThis study suggests that the prevalence of SARS‐CoV‐2 may have been underestimated. Wider testing strategies may lead to revealing more SARS‐CoV‐2 cases.