Contact Tracing during Coronavirus Disease Outbreak, South Korea, 2020.

We analyzed reports for 59,073 contacts of 5,706 coronavirus disease (COVID-19) index patients reported in South Korea during January 20-March 27, 2020. Of 10,592 household contacts, 11.8% had COVID-19. Of 48,481 nonhousehold contacts, 1.9% had COVID-19. Use of personal protective measures and social distancing reduces the likelihood of transmission.

Estimation of heat-related deaths during heat wave episodes in South Korea (2006-2017).

In 2016, South Korea experienced extremely high temperatures and the Korea Centre for Disease Control and Prevention (KCDC) reported 17 heat-caused deaths during these heat waves, most due to heat stroke. Because the reported number of heat-caused deaths is only part of the total deaths associated with heat waves, we aimed to estimate attributable deaths during heat wave episodes. We linked mortality to meteorological data in 16 regions in South Korea and estimated relative risk at or above threshold of maximum temperature during summer using generalized linear regression models after controlling for confounders. We computed overall, age-, sex-, and cause-specific attributable deaths from 2006 to 2017. With a 1.5% increase in all-cause mortality per 1 °C increase in concurrent days' maximum temperature during summer, this study estimates a total of 1440 all-cause deaths associated with heat waves during the 2006-2017 study period in South Korea. We estimate that 343 deaths in 2016 can be ascribed to heat waves, which is approximately 20 times more than the number reported by the KCDC (17 heat-caused deaths). This study addresses attributable heat wave deaths in South Korea and illustrates that the reports of medically classified heat-caused deaths seriously underestimate the number of deaths attributable to heat waves. Our findings may enable the implementation and reinforcement of government- and individual-level management strategies for heat waves.

The spread of pandemic H1N1 2009 by age and region and the comparison among monitoring tools.

This report describes the pattern of the spread of the pandemic H1N1 2009 and compares 3 monitoring tools until the 57th week or January 31, 2010. The 1st week was from December 28th, 2008 to January 3rd, 2009. A total of 740,835 patients were reported to be infected with pandemic H1N1 2009 and 225 patients were reported to have died of pandemic H1N1 2009. The number of patients aged from 7 to 12 was the largest (183,363 patients in total) but the virus spread and then was suppressed most quickly among the children between 13 and 18. The region-determinant incidence of patients showed diverse patterns according to regions. The peak of the ILI per thousand was at the 45th week, the number of antiviral prescriptions reached its peak at the 44th week, and the peak based on reported patients was the 46th week. As of February 3 2010, the outbreak passed through the peak and has gradually subsided. Now it is time for the government and the academic world to review this outbreak, efficacy of vaccination, and further preparation and response for the next pandemic.

Timeliness of national notifiable diseases surveillance system in Korea: a cross-sectional study.

BACKGROUND: With the increase of international travels, infectious disease control is gaining a greater importance across regional borders. Adequate surveillance system function is crucial to prevent a global spread of infectious disease at the earliest stage. There have been limited reports on the characteristics of infectious disease surveillance in Asia. The authors studied the timeliness of the Korean National Notifiable Disease Surveillance System with regard to major notifiable diseases from 2001 to 2006. METHODS: Six notifiable infectious diseases reported relatively frequently were included in this study. Five diseases were selected by the criteria of reported cases > 100 per year: typhoid fever, shigellosis, mumps, scrub typhus, and hemorrhagic fever with renal syndrome. In addition, dengue fever was also included to represent an emerging disease, despite its low number of cases. The diseases were compared for the proportion notified within the recommended time limits, median time lags, and for the cumulative distribution of time lags at each surveillance step between symptom onset and date of notification to the Korea Centers for Disease Control and Prevention (KCDC). RESULTS: The proportion of cases reported in time was lower for disease groups with a recommended time limit of 1 day compared with 7 days (60%-70% vs. > 80%). The median time from disease onset to notification to KCDC ranged between 6 and 20 days. The median time from onset to registration at the local level ranged between 2 and 15 days. Distribution of time lags showed that main delays arose in the time from onset to diagnosis. There were variations in timeliness by disease categories and surveillance steps. CONCLUSION: Time from disease onset to diagnosis generally contributed most to the delay in reporting. It is needed to promote public education and to improve clinical guidelines. Rapid reporting by doctors should be encouraged, and unification of recommended reporting time limit can be helpful. Our study also demonstrates the utility of the overall assessment of time-lag distributions for disease-specific strategies to improve surveillance.

Tuberculosis prevention and care in Korea: Evolution of policy and practice.

Tuberculosis (TB) in Korea remains a serious health problem with an estimated 77 per 100,000 incidence rate for 2016. This makes Korea as the only OECD country with high incidence of TB. The government has increased budgets and strengthened patient management policies since 2011. The management of latent tuberculosis was added to the response with strengthened and extensive contact investigations in the five-year tuberculosis control plan (2013-2017) and implementation was established in 2013. Due to these efforts Korea has achieved an average 5.2% reduction annually in tuberculosis incidence rate between 2011 and 2016. To further expedite the reduction of the TB burden the government has introduced additional measures including mandatory screening of latent tuberculosis infection for community workers in congregate settings including daycare centers for children, kindergarten, and teachers in schools and health care workers in clinics and hospitals to solve the problems identified through contact investigations in 2017. Providing high quality free diagnosis and treatment of active TB including for multidrug resistant TB combined with active contact investigations is the mainstay of the current programmatic response in Korea. However, the limitation of existing tools for LTBI pose challenge including absence of best mechanism for effective communication with professionals and the public, the need for at least 3 months of treatment and the risk of side effects. Developing effective tools will help to overcome these challenges.

Tuberculosis Notification Completeness and Timeliness in the Republic of Korea During 2012-2014.

OBJECTIVES: Completeness and timeliness are key attributes of accurate disease surveillance. This study aimed to evaluate the completeness and timeliness of tuberculosis (TB) notification in the Republic of Korea, by comparing notification data from the Korean National Tuberculosis Surveillance System and reimbursement data from the National Health Insurance. METHODS: We evaluated reimbursement data from 103,075 cases (2012-2014) and surveillance data from 215,055 cases (2011-2015); cases were matched using Resident Registration Numbers. Completeness was evaluated using notifications that were reported within 365 days of the corresponding insurance claim. Timeliness was evaluated using the delay between starting TB treatment and the corresponding notification. Multivariate logistic regression analysis was used to analyze factors that affected completeness (e.g., sex, age, institution type, and nationality). RESULTS: The completeness values were 90.0% in 2012 (33,094/36,775), 93.0% in 2013 (31,445/33,803), and 94.0% in 2014 (30,537/32,497). The rates of notification within 7 days of the corresponding claim were 81.6% in 2012 (27,323/33,489), 79.8% in 2013 (25,469/31,905), and 80.4% in 2014 (24,891/30,978). Increases over time were observed in the sex-, age-, institution type-, and nationality-specific analyses. Multivariate analyses revealed that completeness was affected by institution type [hospitals: odds ratio (OR) = 1.82, p < 0.001; general hospitals: OR = 4.18, p < 0.001] and nationality (native Korean status: OR = 1.48, p < 0.001). CONCLUSION: Notification completeness exhibited a 4.0% increase during 2012-2014 in Korea, and institution type and nationality significantly affected the completeness of TB notifications.