Seroprevalence study of SARS-CoV-2 antibodies in community based on participants in the 2020 Korea National Health and Nutrition Examination Survey (KNHANES)

• Published in: Epidemiology and health 2022-02, p.e2022028
• Main Authors: Kim, Ah-Ra, Minn, Dohsik, Kim, SuHwan, Do, HyeonNam, Kim, Brian Byoungguk, Choi, Young Sill, Kim, Dong-Hyun, Oh, Eun-Jee, Oh, Kyungwon, Kwon, Donghyok, Kwon, Jun-Wook, Kim, Sung Soon, Lee, Junewoo
• Format: Article
• Language: English
• ISSN: 2092-7193
• DOI: 10.4178/epih.e2022028

The Korea National Health and Nutrition Examination Survey (KNHANES) is a nationwide cross-sectional surveillance system that assesses the health and nutritional status of the Korean population. To evaluate the occurrence of SARS-CoV-2 infection in the community, we investigated the presence of antibodies against SARS-CoV-2 using the sera of KNHANES participants. The subjects were recruited between April 24, 2020, and December 12, 2020. A total of 5,284 subjects aged 10-90 years from 17 regions participated in the survey. SARS-CoV-2 antibodies were screened using the Elecsys Anti-SARS-CoV-2 assay. Positive samples were verified using four different SARS-CoV-2 antibody assays and the plaque reduction neutralizing test (PRNT). The final seropositivity criteria were defined as a positive screening test and at least one positive out of the five additional tests. The distribution of survey participants was as follows: 49.2% (2,600/5,284) were from a metropolitan area, 48.9% were middle-aged (in their 40s and 60s) and 19.3% were in their 20s or younger. The seropositivity rate among the participants was 0.09% (5/5,284). Out of the five antibody-positive subjects, three had a history of infection, of whom, two were infected abroad while one was infected through a local cluster outbreak. The low seroprevalence of SARS-CoV-2 antibody in Korea indicates the fewer COVID-19 patients due to succeed of COVID-19 management measures. Moreover, asymptomatic infections were also detected fewer due to active PCR testing. However, hidden infections may still be prevalent in the community, thus requiring continuous quarantine and vaccination.