To describe and evaluate epidemiological investigation. and containment measures implemented in Busan, where 108 cases were confirmed with coronavirus disease 2019 (COVID-19) between February 21 and March 24, 2020. Any individual who tested positive for COVID-19 was classified as a confirmed case. Measures were taken to identify the source of infection and trace and quarantine contacts. Serial intervals were estimated and the effective reproduction number (R_t) was computed. Of the total 18,303 COVID-19 tests performed between January 16 and March 24 in Busan, 108 yielded positive. (positive test rate: 0.6%). All confirmed cases were placed in isolation at hospitals. Of the 108 confirmed cases, 59 (54.6%) were female. The most common age group was 20-29 years with 37 cases (34.3%). Regarding symptoms at the time of diagnosis, cough (n=38, 35.2%) and fever (n=34, 31.5%) were most common; 12 cases (11.1%) were asymptomatic. The source of infection was identified in 99 cases (91.7%). A total of 3,223 contacts were identified and quarantined. Household contacts accounted for 196, and the household secondary attack rate (SAR) was 8.2% (95% confidence interval [CI] 4.7-12.9%). The mean serial interval was estimated to be 5.54 days (95% CI 4.08-7.01 days). After February 26, R_t remained below 1 in Busan. : The early containment strategy implemented in Busan shows that control is possible if outbreaks are of limited scope. In preparation for future outbreaks, public health and healthcare systems should be re-examined and put in a ready state.

Kwak M, et al. J Korean Med Sci. 2017 Dec;32(12):1974-1983. https://doi.org/10.3346/jkms.2017.32.12.1974

This study investigated the treatment outcomes, and factors affecting the outcomes, of new tuberculosis (TB) patients in Busan, South Korea. We retrospectively analysed the citywide TB registry data (collected for the Korean National TB Surveillance System) of new TB patients registered in Busan from January 2014 to December 2015. A total of 4732 patients were included in this study (mean age, 52.5 ± 19.9 years; 58.4% male). The overall treatment success rate was 83.9% (cured, 20.2%; completed, 63.7%); 8.0% of patients died, and 3.6% were lost to follow-up. In multivariate analyses, a higher rate of loss to follow-up was associated with foreign nationality, registered as TB-positive at least twice, and being in Q4 (fourth quintile) or Q5 (fifth quintile) of the regional deprivation index. Conversely, a lower rate of loss to follow-up was associated with female gender, smear-positive for pulmonary TB (PTB), and the treatment outcome being reported by a public health centre. Higher mortality was associated with old age (≥ 75 years), smear-positive PTB, treatment outcome being reported by the hospital, and being registered as TB-positive twice. Lower mortality was associated with female gender, treatment outcome being reported by a public health centre or clinic, and Q5 of the regional deprivation index. Treatment outcomes of new TB patients were sub-optimal in Busan. TB control programs should maintain close monitoring and provide greater socioeconomic support to patients at high risk of poor treatment outcomes.

Background: The prevalence of multiple chronic conditions (MCC), defined as several coexisting chronic conditions, has increased with the aging of society. MCC is associated with poor outcomes, but most comorbid diseases in asthma patients have been evaluated as asthma-associated diseases. We investigated the morbidity of coexisting chronic diseases in asthma patients and their medical burdens. Methods: We analyzed data from the National Health Insurance Service-National Sample Cohort for 2002–2013. We defined MCC with asthma as a group of one or more chronic diseases in addition to asthma. We analyzed 20 chronic conditions, including asthma. Age was categorized into groups 1–5 (< 10, 10–29, 30–44, 45–64, and ≥ 65 years, respectively). The frequency of medical system use and associated costs were analyzed to determine the asthma-related medical burden in patients with MCC. Results: The prevalence of asthma was 13.01%, and the prevalence of MCC in asthmatic patients was 36.55%. The prevalence of MCC with asthma was higher in females than males and increased with age. The significant comorbidities were hypertension, dyslipidemia, arthritis, and diabetes. Dyslipidemia, arthritis, depression, and osteoporosis were more common in females than males. Hypertension, diabetes, COPD, coronary artery disease, cancer, and hepatitis were more prevalent in males than females. According to age, the most prevalent chronic condition in groups 1 and 2 was depression, dyslipidemia in group 3, and hypertension in groups 4 and 5. Older age, low income, and severe disability were independent risk factors for MCC in patients with asthma. The frequency of asthma-related medical system use and asthma-associated costs increased with increasing numbers of coexisting chronic diseases. Conclusion: Comorbid chronic diseases in asthma patients differed according to age and sex. The asthma-related-medical burdens were highest in patients with five or more chronic conditions and groups 1 and 5.

OBJECTIVES: In July 2019, there were multiple reports on patients with hepatitis A among the visitors of a restaurant in Busan. The current study presents the results of an epidemiological investigation and outlines the supplementary measures that would help with hepatitis A control.METHODS: A cohort study was conducted for all 2,865 customers who visited restaurant A from June to July. Using a standardized questionnaire, participants reported the presence of hepatitis A symptoms and whether they had consumed any of 19 food items. As for participants who had visited public health centers, their specimens were collected.RESULTS: From the study cohort, 155 participants (5.4%) had confirmed hepatitis A. The epidemic curve was unimodal, and the median number of days from the restaurant visit to symptom onset was 31 days. A genotype analysis indicated that 89 of 90 tested patients had hepatitis A virus (HAV) genotype 1A. The results of a multivariate logistic regression analysis indicated that the ingestion of salted clams increased the risk of hepatitis A by 68.12 times (95% confidence interval [CI], 9.22 to 510.87). In an unopened package of salted clams found and secured through traceback investigation, HAV genotype 1A was detected.CONCLUSIONS: To prevent people from ingesting uncooked clams, there needs to be more efforts to publicize the dangers of uncooked clams; the food sampling test standards for salted clams should also be expanded. Furthermore, a laboratory surveillance system based on molecular genetics should be established to detect outbreaks earlier.