Acknowledgement
We deeply appreciate the staff of the infectious disease team in six community health centers in Jeju Province who performed epidemiological investigations on confirmed cases of COVID-19; the RT-PCR test staff of the Jeju Institute of Health and Environment who conducted RT-PCR tests to confirm COVID-19; and the staff of Team for Infection Control of Jeju Province Office who analyzed epidemiological investigation reports and decided on the countermeasures.
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