Epidemiol Health.  2023;45(1):e2023075. 10.4178/epih.e2023075.

Korea Seroprevalence Study of Monitoring of SARS-COV-2 Antibody Retention and Transmission (K-SEROSMART): findings from national representative sample

• Han J
• Baek HJ
• Noh E
• Yoon K
• Kim JA
• Ryu S
• Lee KO
• Park NY
• Jung E
• Kim S
• Lee H
• Hwang YS
• Jung J
• Lee HJ
• Cho Si
• Oh S
• Kim M
• Oh CM
• Yu B
• Hong YS
• Kim K
• Jung S
• Han MA
• Lee MS
• Lee JJ
• Hwangbo Y
• Yim HW
• Kim YM
• Lee J
• Lee WY
• Park JH
• Oh S
• Jo HS
• Kim H
• Kang G
• Nam HS
• Lee JH
• Oh GJ
• Shin MH
• Ryu S
• Hwang TY
• Park SW
• Kim SK
• Seol R
• Park KS
• Kim SY
• Kwon Jw
• Kim SS
• Kim B
• Lee JW
• Jang EY
• Kim AR
• Nam J
• The Korea Community Health Survey Group
• Lee SY
• Kim DH

• KMID: 2548035
• DOI: http://doi.org/10.4178/epih.e2023075

Abstract

OBJECTIVES
We estimated the population prevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including unreported infections, through a Korea Seroprevalence Study of Monitoring of SARS-CoV-2 Antibody Retention and Transmission (K-SEROSMART) in 258 communities throughout Korea.
METHODS
In August 2022, a survey was conducted among 10,000 household members aged 5 years and older, in households selected through two stage probability random sampling. During face-to-face household interviews, participants self-reported their health status, COVID-19 diagnosis and vaccination history, and general characteristics. Subsequently, participants visited a community health center or medical clinic for blood sampling. Blood samples were analyzed for the presence of antibodies to spike proteins (anti-S) and antibodies to nucleocapsid proteins (anti-N) SARS-CoV-2 proteins using an electrochemiluminescence immunoassay. To estimate the population prevalence, the PROC SURVEYMEANS statistical procedure was employed, with weighting to reflect demographic data from July 2022.
RESULTS
In total, 9,945 individuals from 5,041 households were surveyed across 258 communities, representing all basic local governments in Korea. The overall population-adjusted prevalence rates of anti-S and anti-N were 97.6% and 57.1%, respectively. Since the Korea Disease Control and Prevention Agency has reported a cumulative incidence of confirmed cases of 37.8% through July 31, 2022, the proportion of unreported infections among all COVID-19 infection was suggested to be 33.9%.
CONCLUSIONS
The K-SEROSMART represents the first nationwide, community-based seroepidemiologic survey of COVID-19, confirming that most individuals possess antibodies to SARS-CoV-2 and that a significant number of unreported cases existed. Furthermore, this study lays the foundation for a surveillance system to continuously monitor transmission at the community level and the response to COVID-19.

Keyword

COVID-19; Seroepidemiologic studies; Antibody; Community Health Survey; Sampling studies