Evaluating the spatial and temporal patterns of the severe fever thrombocytopenia syndrome in Republic of Korea.

Severe fever with thrombocytopenia syndrome (SFTS) is a new infectious disease with a high mortality rate and increased incidence in Republic of Korea since the first case was reported in 2013. The average mortality rate varies by region and year but remains high in Asia. This study aimed to evaluate the spatial and temporal patterns of SFTS cases reported to the national Disease Control and Prevention Agency (KDCA). We analysed the spatial and temporal distribution of SFTS and observed changes in areas vulnerable to the disease. We analysed data concerning 1086 confirmed SFTS patients from 2013 to 2019 categorized according to the 247 district level administrative units. To better understand the epidemiology of SFTS, we carried out spatiotemporal analyses on a yearly basis and also calculated and mapped spatial clusters of domestic SFTS by global (regional) and local Moran's indices. To observe the annual changes in SFTS incidence rate, scan statistics for each city and district were calculated. The incidence rate showed significant clustering in specific regions, which reoccurred annually in some regions. In Republic of Korea, SFTS clusters have been expanding into the southern regions, with annual clusters concentrated between May and October. This pattern allows prediction of SFTS occurrences through spatiotemporal analysis, which makes it possible to guide measures of disease prevention.

Associations of regional-level perceived stress and depression with health-related quality of life in Korean adults: a multilevel analysis of 2017 Korea Community Health Survey data.

OBJECTIVES: We examined the associations of individual and regional-level perceived stress and depression with health-related quality of life (HRQOL) in Korean adults. METHODS: We used data from the 2017 Korea Community Health Survey, which included 216,713 adults living within 254 municipal districts. As individual-level independent variables, perceived stress (higher vs. lower) and depression (Patient Health Questionnaire-9 ≥10) were defined. Regional-level age-adjusted rates of perceived stress (%) and depression (%) were created for 254 municipal districts and categorized into quartiles to generate regional levels of stress and depression. HRQOL was defined as the individual-level EuroQol 5-dimensional index×100. A multilevel analysis was performed to identify the relationship between individual or regional-level independent variables and individual HRQOL. RESULTS: In the null model, the proportions of individual variation in the HRQOL explained by region were 1.7% and 2.7% for men and women, respectively. When adjusted with all individual-level variables, regional stress and depression, as well as individual-level perceived stress and depression, were significantly related to HRQOL for both genders. In the full model including all variables, the decrease in HRQOL from the first to the fourth quartile group of regional stress was greater in women (-1.09; 95% confidence interval [CI], -1.87 to -0.31) than in men (-0.65; 95% CI, -1.04 to -0.26). CONCLUSIONS: Our results suggest that regional-level perceived stress and depression, as well as individual-level perceived stress and depression, are inversely associated with individual HRQOL.

Time-variant reproductive number of COVID-19 in Seoul, Korea.

OBJECTIVES: To estimate time-variant reproductive number (Rt) of coronavirus disease 19 based on either number of daily confirmed cases or their onset date to monitor effectiveness of quarantine policies. METHODS: Using number of daily confirmed cases from January 23, 2020 to March 22, 2020 and their symptom onset date from the official website of the Seoul Metropolitan Government and the district office, we calculated Rt using program R's package "EpiEstim". For asymptomatic cases, their symptom onset date was considered as -2, -1, 0, +1, and +2 days of confirmed date. RESULTS: Based on the information of 313 confirmed cases, the epidemic curve was shaped like 'propagated epidemic curve'. The daily Rt based on Rt_c peaked to 2.6 on February 20, 2020, then showed decreased trend and became <1.0 from March 3, 2020. Comparing both Rt from Rt_c and from the number of daily onset cases, we found that the pattern of changes was similar, although the variation of Rt was greater when using Rt_c. When we changed assumed onset date for asymptotic cases (-2 days to +2 days of the confirmed date), the results were comparable. CONCLUSIONS: Rt can be estimated based on Rt_c which is available from daily report of the Korea Centers for Disease Control and Prevention. Estimation of Rt would be useful to continuously monitor the effectiveness of the quarantine policy at the city and province levels.

Coronavirus Disease Outbreak in Call Center, South Korea.

We describe the epidemiology of a coronavirus disease (COVID-19) outbreak in a call center in South Korea. We obtained information on demographic characteristics by using standardized epidemiologic investigation forms. We performed descriptive analyses and reported the results as frequencies and proportions for categoric variables. Of 1,143 persons who were tested for COVID-19, a total of 97 (8.5%, 95% CI 7.0%-10.3%) had confirmed cases. Of these, 94 were working in an 11th-floor call center with 216 employees, translating to an attack rate of 43.5% (95% CI 36.9%-50.4%). The household secondary attack rate among symptomatic case-patients was 16.2% (95% CI 11.6%- 22.0%). Of the 97 persons with confirmed COVID-19, only 4 (1.9%) remained asymptomatic within 14 days of quarantine, and none of their household contacts acquired secondary infections. Extensive contact tracing, testing all contacts, and early quarantine blocked further transmission and might be effective for containing rapid outbreaks in crowded work settings.

Clinical and Laboratory Findings of Middle East Respiratory Syndrome Coronavirus Infection.

There is a paucity of data regarding the differentiating characteristics of patients with laboratory-confirmed and those negative for Middle East respiratory syndrome coronavirus (MERS-CoV) in South Korea. This hospital-based retrospective study compared MERS-CoV-positive and MERS-CoV-negative patients. A total of seven positive patients and 55 negative patients with a median age of 43 years (P = 0.845) were included. No statistical differences were observed with respect to their sex and the presence of comorbidities. At the time of admission, headache (28.6% vs. 3.6%; odds ratio [OR], 10.60; 95% confidence interval [CI], 1.22-92.27), myalgia (57.1% vs. 9.1%; OR, 13.33; 95% CI, 2.30-77.24), and diarrhea (57.1% vs. 14.5%; OR, 7.83; 95% CI, 1.47-41.79) were common among MERS-CoV-positive patients. MERS-CoV-positive patients were more likely to have a low platelet count (164 ± 76.57 vs. 240 ± 79.87) and eosinophil (0.27 ± 0.43 vs. 2.13 ± 2.01; P = 0.003). Chest radiography with diffuse bronchopneumonia was more frequent in MERS-CoV-positive patients than in negative patients (100% vs. 62.5%; P = 0.491). The symptoms of headache, myalgia, and diarrhea, as well as laboratory characteristics, including low platelet counts and eosinophil, and chest X-ray showing diffuse bronchopneumonia might enhance the ability to detect patients in South Korea infected with MERS-CoV.

Age-related differences in diabetes care outcomes in Korea: a retrospective cohort study.

BACKGROUND: Age-related differences in diabetes outcomes are important both for clinical and policy considerations. To clarify the basis of such differences, we investigated patterns of associations for age in relation to hospitalization and glycemic control and examined the role of other factors. METHODS: 4471 patients with diabetes aged 40-79 years were drawn from a retrospectively retrieved National Health Insurance Cohort. Using logistic regression, risk factors measured over the two years (2007-2008) were examined for their associations with hospitalization and poor glycemic control during the last year (2009) of follow-up. RESULTS: Compared to the middle-aged patients, older patients were more likely to have been hospitalized (Adjusted odds ratio (OR(adjusted)) = 1.97(95% CI = 1.28, 3.04) for the oldest group (ages 70-79) vs youngest group (ages 40-49)) but less likely to have poor glycemic control (OR(adjusted) = 0.45 (95% CI = 0.37, 0.56) for the oldest group vs youngest group). Older patients were also less likely to be obese but had more complications, longer duration of diabetes, lower continuity of care, and higher blood pressure and total cholesterol level. The pattern of associations for hospitalization and glycemic control was not uniform across the risk factors, sharing only a few common factors such as the duration of diabetes and blood pressure. In general, poor glycemic control was affected predominantly by metabolic management, while hospitalization was strongly related to functional status (i.e., number of complications) and care quality measures (i.e., continuity of care). CONCLUSION: Hospitalization was higher among the older diabetic patients, despite better glycemic control. Factors were differently associated with the two diabetes-related outcomes, providing more comprehensive risk profiles for hospitalization. The co-existence of improved glycemic control and increased hospitalization among older diabetic patients suggests an extension of a geriatric evaluation to wider functional and comorbidity status.

Fluctuation of peripheral blood T, B, and NK cells during a menstrual cycle of normal healthy women.

Cyclical hormonal changes during an ovarian cycle may affect immune responses, which is crucial for the embryonic implantation. We aim to investigate whether the levels and activity of T, B, and NK cells change during a menstrual cycle. Twenty-two normally cycling women were enrolled and peripheral blood was drawn serially during a menstrual cycle. Intracellular cytokine expression of CD3(+)CD4(+) and CD3(+)CD8(+) cells, and Th1/Th2 cytokine-producing T cell ratios were determined using flow cytometric analysis. NK cell cytotoxicity was measured by flow cytometric analysis at E:T ratios of 50:1, 25:1, and 12.5:1 and also using LU at 20%. Proportions (percentage) of CD3(+) (p = 0.046) and CD3(+)CD4(+) (p = 0.002) T cells were increased in the follicular phase compared with the luteal phase. The levels of CD3(-)CD56(+) (p = 0.010) and CD3(-)CD56(dim) (p = 0.012) NK cells and NK cytotoxicity at E:T ratio of 50:1, 25:1, and 12.5:1 and LU at 20% were significantly increased in the luteal phase compared with the follicular phase. Even though IL-10-producing CD3(+)CD4(+) T cells were significantly lower in the midluteal phase as compared with the early follicular phase, proportions of CD19(+) B cells, CD3(+)CD56(+) NKT cells, Th1 cytokine-producing T cell subsets, and ratios of Th1/Th2 cytokine-producing T cells were not significantly changed during a menstrual cycle. We conclude that peripheral blood NK and T cell levels as well as NK cytotoxicity are changed during a menstrual cycle. Neuroendocrine regulation on immune responses is suggested during an ovarian cycle, which may be critical for embryonic implantation and pregnancy.

[Related factors for the initiation of smoking in high school students based on the transtheoretical model].

OBJECTIVE: This study was conducted to investigate the relationship between the intention of smoking and its related factors in high school students. METHODS: Our study subjects were 1,203 high school students who resided in one city and in one county region. We conducted a self-administered questionnaire survey from June 7 to June 19, 2004. Both the decisional balance and temptation inventory showed high reliability estimates. We provided good fit for the 12-item decisional balance inventory and the 10-item temptation inventory by using a confirmatory factor analysis. We also used multiple logistic regression analysis to identify the major contributing factors for the intention to start smoking. RESULTS: On the univariate analysis, the subjects who were female, the 2nd and 3rd grade students,the students in vocational high school, the ex-drinkers or current drinkers, and ex-smokers were found to be significantly more distributed in the groups with intention to start smoking. Except for the concept of the cons, the group with intention to start smoking showed significantly higher standardized T scores for the 7 concepts of decisional balance and temptations. On the multiple logistic regression analysis, the females, the 2nd and 3rd grade students, the students in vocational high school, the experience of cigarette smoking and low T score of the cons were significantly related to the intention to start smoking. CONCLUSIONS: The intention to start smoking in high school students was affected by various factors such as gender, the school grade and the experience of smoking. Therefore, further research should be conducted for providing the essential data for developing a brief instrument for selecting the groups with intention of starting smoking among adolescents.