The Importance of Mandatory COVID-19 Diagnostic Testing Prior to Release from Quarantine.

A 14-day quarantine is implemented in many countries in response to the coronavirus disease pandemic. Korea implemented a mandatory quarantine for those who had close contact with infected patients and those returning from abroad. The present study explored the implications of mandatory coronavirus disease 2019 testing before releasing individuals from the 14-day quarantine in Incheon, Korea. From February 11 to July 5, 2020, 19,296 people were self-quarantined, and 56 (0.3%) of them were confirmed cases of COVID-19. Twenty (35.7%) were identified through the reporting of symptoms during quarantine, and 32 (57.1%) were identified using mandatory pre-release RT-PCR tests. Among the 32, 14 (25%) individuals reported mild symptoms and 18 (32.1%) were asymptomatic. It is suggested that mandatory diagnostic testing prior to release and the symptom-based surveillance after the 14-day quarantine may help control delayed or asymptomatic COVID-19 cases.