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

Nobutoshi Nawa; Jin Kuramochi; Shiro Sonoda; Yui Yamaoka; Yoko Nukui; Yasunari Miyazaki; Takeo Fujiwara

doi:10.1002/jgf2.408

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

J Gen Fam Med. 2020 Dec 16;22(3):160-162. doi: 10.1002/jgf2.408. eCollection 2021 May.

Authors

Nobutoshi Nawa¹, Jin Kuramochi², Shiro Sonoda², Yui Yamaoka³, Yoko Nukui⁴, Yasunari Miyazaki⁵, Takeo Fujiwara³

Affiliations

¹ Department of Medical Education Research and Development Tokyo Medical and Dental University Tokyo Japan.
² Kuramochi Clinic Interpark Utsunomiya Japan.
³ Department of Global Health Promotion Tokyo Medical and Dental University Tokyo Japan.
⁴ Department of Infection Control and Prevention, Medical Hospital Tokyo Medical and Dental University Tokyo Japan.
⁵ Department of Respiratory Medicine Tokyo Medical and Dental University Tokyo Japan.

Abstract

Background: A 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.

Methods: The 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.

Results: Three positive afebrile cases were confirmed. The estimated unweighted prevalence and weighted prevalence of SARS-CoV-2 infection were 0.40% and 1.23%, respectively.

Conclusions: This 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.

Keywords: communicable diseases; coronavirus infections; seroepidemiologic studies.