Risk factors for transmission in a COVID-19 cluster infection in a high school in the Republic of Korea

• Published in: Osong public health and research perspectives Vol. 14; no. 4; pp. 252 - 262
• Main Authors: Jeon, Jin-Hwan, Kang, Su Jin, Jeong, Se-Jin, Jang, Hyeon-Cheol, Park, Young-Joon, Lee, Sang-Eun
• Format: Journal Article
• Language: English
• Published: Korea Disease Control and Prevention Agency 01.08.2023
• Subjects: covid-19; epidemiology; Original; risk factors; surveys and questionnaires; video analysis
• ISSN: 2210-9099; 2233-6052
• DOI: 10.24171/j.phrp.2023.0125

Objectives: This study aimed to examine the scale, characteristics, risk factors, and modes of transmission in a coronavirus disease 2019 (COVID-19) outbreak at a high school in Seoul, Republic of Korea.Methods: An epidemiological survey was conducted of 1,118 confirmed cases and close contacts from a COVID-19 outbreak at an educational facility starting on May 31, 2021. In-depth interviews, online questionnaires, flow evaluations, and CCTV analyses were used to devise infection prevention measures. Behavioral and spatial risk factors were identified, and statistical significance was tested.Results: Among 3rd-year students, there were 33 confirmed COVID-19 cases (9.6%). Students who used a study room in the annex building showed a statistically significant 4.3-fold elevation in their relative risk for infection compared to those who did not use the study room. Moreover, CCTV facial recognition analysis confirmed that 17.8% of 3rd-year students did not wear masks and had the lowest percentage of mask-wearers by grade. The air epidemiological survey conducted in the study room in the annex, which met the 3 criteria for a closed space, confirmed that there was only 10% natural ventilation due to the poor ventilation system.Conclusion: To prevent and manage the spread of COVID-19 in educational facilities, advance measures that consider the size, operation, and resources of each school are crucial. In addition, various survey methodologies should be used in future studies to quickly analyze a wider range of data that can inform an evidence-based quarantine response.