'Silent Spreaders' Unaware of COVID-19 Infection Are Three Times More Common Among Young People

Disease Control Headquarters, COVID-19 Antibody Survey Results
Comparison and Analysis of Undiagnosed Antibody Positivity Rates
General Population 0.07% · Early 20s Males 0.22%

A conscript is undergoing a COVID-19 test. <이미지:Yonhap News>

[Asia Economy Reporter Choi Dae-yeol] The government conducted a survey on over 8,200 people to determine whether they had contracted the novel coronavirus infection (COVID-19), revealing that 16 individuals had been infected in the past but were never officially diagnosed. This was based on an examination of whether COVID-19 antibodies had developed, with a notably higher number of undiagnosed antibody-positive cases found particularly among younger age groups. The antibody positivity rate in groups targeting young people was about three times higher than that found in surveys of the general population.

According to the COVID-19 antibody survey results announced by the Central Disease Control Headquarters on the 23rd, the third round of the National Health and Nutrition Examination Survey was conducted from mid-August to the end of last month. Among 1,379 participants, 3 showed antibody-positive reactions. Of these, 2 were confirmed COVID-19 cases diagnosed immediately after arriving from overseas, and the remaining 1 was an undiagnosed case in the community.

In the earlier second survey conducted from June to August, 1 out of 1,440 participants also showed an undiagnosed antibody-positive reaction. Additionally, antibody tests conducted on 6,859 military conscripts between September and October found 25 positive cases. Among these, 10 had been confirmed COVID-19 cases, while the remaining 15 were undiagnosed antibody-positive individuals in the community.

COVID-19 antibody test results from this year's Korea National Health and Nutrition Examination Survey (top table) and antibody test results for military enlistment candidates (bottom table)

Based on these results, authorities analyzed that undiagnosed infected individuals exist within the community, especially among younger age groups. The undiagnosed antibody positivity rate was about 0.07% among the general population, but in the group of military conscripts mostly composed of young men in their early 20s, it was 0.22%, more than three times higher.

Director Jeong Eun-kyung stated at the briefing, "Young age groups often experience asymptomatic or mild infections and do not seek medical treatment or testing, yet remain socially active, which significantly increases the risk of spreading infections within the community. It is necessary to strengthen quarantine management for those in their early 20s."

On the 23rd, one day before the social distancing level 2 upgrade in the Seoul metropolitan area, a COVID-19 related closure notice is posted at a store in Myeongdong, Jung-gu, Seoul. Photo by Mo Honam munonam@

However, authorities noted that extrapolating the number of undiagnosed patients across society based on these positivity rates has limitations. The National Health and Nutrition Examination Survey targets around 1,400 people per survey, which is a small sample size for generalization, and the military conscript group is limited to males in their early 20s, representing a very narrow age range. Nevertheless, considering the characteristics of COVID-19, many young patients experience mild or no symptoms, making it likely that "silent transmission" is spreading primarily among this group.

Director Jeong added, "To strengthen the prevention of infection spread among young age groups, we will collaborate with the Ministry of Education to expand non-face-to-face classes at universities, encourage the reduction of small in-person gatherings, and enhance quarantine management measures in multi-use facilities such as dormitories and cafeterias. We will also strengthen management and inspections of facilities where young people gather densely, such as academies and study cafes."

This content was produced with the assistance of AI translation services.