This study aims to evaluate the risk assessments of coronavirus 2019 (COVID-19) in the Korea Centers for Disease Control and Prevention (KCDC), from the point of detection to the provision of basic information to the relevant public health authorities. Methods: To estimate the overall risk of specific public health events, probability, and impact at the country-level were evaluated using available information. To determine the probability of particular public health events, the risk of importation and risk of transmission were taken into consideration. KCDC used 5 levels ("very low," "low," "moderate," "high," and "very high") for each category and overall risk was eventually decided. Results: A total of 8 risk assessments were performed on 8 separate occasions between January 8 th to February 28 th , 2020, depending on the detection and report of COVID-19 cases in other countries. The overall risk of the situation in each assessment increased in severity over this period: "low" (first), "moderate" (second), "high" (third), "high" (fourth), "high" (fifth), "high" (sixth), "high" (seventh), and "very high" (eighth). Conclusion: The KCDC's 8 risk assessments were utilized to activate national emergency response mechanisms and eventually prepare for the pandemic to ensure the containment and mitigation of COVID-19 with non-pharmaceutical public health measures.

The Japanese encephalitis (JE) vaccine was introduced to the national immunization program in 1985, which has led to a dramatic decrease in the number of reported cases, but JE continues to occur in foreign nationals residing in or traveling to Korea. Although the incidence is low, this study demonstrated that more Koreans were infected with JE than foreign-born expatriates. The incidence rates of Korean-born nationals were between 0.01 and 0.08 cases per 100,000. In contrast, the incidence rates of foreign-born nationals ranged between 0 and 0.26 cases per 100,000. The incidence rates clearly showed that foreign-born expatriates were more at risk, which underscores the importance of vaccination. We recommend heightened surveillance among JE-susceptible individuals and promote vaccination among foreign-born nationals living in Korea.

We identified imported cases of a novel D614A mutation in the spike glycoprotein of SARS-CoV-2 in the South Korea. SARS-CoV-2 harboring the novel mutation was isolated from returning travelers from Uzbekistan. These results emphasized the possibility that new mutations have emerged in that area.