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Updated: Oct 11, 2025

Quantification and Whole Genome Characterization of SARS-CoV-2 RNA in Wastewater and Air Samples
Published on: June 30, 2023
SARS-CoV-2 transmission in schools in Korea: nationwide cohort study
Young June Choe1, Young-Joon Park2, Eun-Young Kim2
1Department of Pediatrics, Korea University Anam Hospital, Seoul, Republic of Korea.
Objective:
There is an urgent public need to readdress the school closure strategies. We aimed to describe the epidemiology of COVID-19 in schools and school-aged children to understand their roles in transmitting SARS-CoV-2 in Korea.
Design:
Retrospective cohort study.
Setting:
All schools in Korea PATIENTS: All school-aged children in Korea.
Interventions:
None (observational study).
Main Outcome Measures:
Incidence rate, proportion of affected schools.
Results:
Between February and December 2020, the incidence rate was lower among school-aged children (63.2-79.8 per 100 000) compared with adults aged 19 and above (130.4 per 100 000). Household was the main route of transmission (62.3%), followed by community (21.3%) and school clusters (7.9%). Among the schools in Korea, 52% of secondary schools had COVID-19 cases, followed by 39% of primary schools and 3% of kindergartens.
Conclusions:
We found that schools and school-aged children aged 7-18 years were not the main drivers of COVID-19 transmission. The major sources of transmission were households.
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