An outbreak of hepatitis A associated with salted clams in Busan, Korea / 한국역학회지

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.

Epidemiological characteristics of and containment measures for COVID-19 in Busan, Korea / 한국역학회지

Objectives@#To describe and evaluate epidemiological investigation results and containment measures implemented in Busan, where 108 cases were confirmed with coronavirus disease 2019 (COVID-19) between February 21, 2020 and March 24, 2020. @*Methods@#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 was computed. @*Results@#Of the total 18,303 COVID-19 tests performed between January 16, 2020 and March 24, 2020 in Busan, 108 yielded positive results (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 was 8.2% (95% confidence interval [CI], 4.7 to 12.9). The mean serial interval was estimated to be 5.54 days (95% CI, 4.08 to 7.01). After February 26, (Rt) remained below 1 in Busan. @*Conclusions@#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.

Epidemiological characteristics of and containment measures for COVID-19 in Busan, Korea / 한국역학회지

Objectives@#To describe and evaluate epidemiological investigation results and containment measures implemented in Busan, where 108 cases were confirmed with coronavirus disease 2019 (COVID-19) between February 21, 2020 and March 24, 2020. @*Methods@#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 was computed. @*Results@#Of the total 18,303 COVID-19 tests performed between January 16, 2020 and March 24, 2020 in Busan, 108 yielded positive results (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 was 8.2% (95% confidence interval [CI], 4.7 to 12.9). The mean serial interval was estimated to be 5.54 days (95% CI, 4.08 to 7.01). After February 26, (Rt) remained below 1 in Busan. @*Conclusions@#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.

Disparities by Age, Sex, Tumor Stage, Diagnosis Path, and Area-level Socioeconomic Status in Survival Time for Major Cancers: Results from the Busan Cancer Registry

Our goal was to examine the effect of area-level deprivation on patient survival time for seven major cancers — stomach, colon, liver, lung, breast, cervix, and thyroid cancer. Data on 10,902 subjects who were diagnosed with major cancers from 2010 and 2011 in Busan were collected regarding the survival time along with several important prognostic factors and an area-level deprivation index was constructed from education, income, unemployment, and welfare assistance, to assess the comprehensive area-level socioeconomic status. A multilevel Cox proportional hazard model was used to investigate the effects of multiple risk factors such as gender, age, tumor stage, diagnosis path, and the area-level deprivation. After adjusting for risk factors the area-level deprivation index was found to be significant in associating with higher hazard rate for several cancers. Estimated hazard ratios (95% CI) were 1.08 (0.99–1.18), 1.23 (1.12–1.36), 1.36 (1.21–1.53) for the second, the third, and the fourth quartile of deprivation index groups, respectively, when compared to the least deprived group. When compared with the least deprived group, the more deprived group showed significant decrease in survival time for major cancers. This novel finding may contribute to the literature regarding the association of area-level socioeconomic status and highlight the importance of careful monitoring of socioeconomic characteristics for cancer prevention and care services.

The Relationship between Microcirculatory Resistance and Fractional Flow Reserve in Patients with Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: It was demonstrated that the fractional flow reserve (FFR) with partial balloon obstruction may have implications for assessing viable myocardium. In a different way, the index of microcirculatory resistance (IMR) was introduced as a useful indicator for assessing microvascular function. We evaluated the relationship between the FFR0.8 and the IMR. SUBJECTS AND METHODS: We studied 48 consecutive patients who had undergone coronary intervention for acute myocardial infarction (AMI). After revascularization using stent(s), an undersized short balloon was positioned inside the stent and inflated to create a specific normalized pressure drop of FFR (distal coronary/aortic pressure=0.80) at rest. The FFR0.8 was obtained during hyperemia with the fixed state balloon-induced partial obstruction. IMR was measured by three injections of saline. The association between the FFR0.8 and the IMR was investigated. RESULTS: The mean age of the patients was 60+/-12 years and 36 (75%) overall presented with ST-segment elevation myocardial infarction. The mean FFR0.8 was 0.68+/-0.06. A statistically significant correlation between the FFR0.8 and the log-transformed IMR(true) (LnIMR(true)) was found through a multivariable linear regression analysis (beta=0.056, p<0.001). Both the FFR0.8 and the LnIMR(true) had a positive correlation with the log-transformed peak troponin I (TnI) with statistical significance (r2=0.119, p=0.017; r2=0.225, p=0.006, respectively). CONCLUSION: There was a positive correlation between the LnIMR(true) and the FFR0.8. Both of the values were associated with peak TnI. Those values may be used as appropriate surrogate measures of microvascular function after AMI.

The Respiratory Morbidities in Late-preterm Infants Compared with the Early-preterm and Term Infants throughout the First Year of Life

PURPOSE: We examined the respiratory morbidities in late-preterm infants compared to those of the early-preterm infants and term infants throughout the first year of life. METHODS: Data were retrospectively collected for 87 late-preterm, 72 early-preterm, and 608 term infants who were admitted to NICU and the nursery of Busan St. Mary's Medical Center from Jan 2007 to Oct 2009. RESULTS: There were significant differences in the proportions of the out-born infants, twin pregnancy, small for gestational age, and Caesarean section in the three groups (P<0.05). Late-preterm and early-preterm infants had longer duration of hospitalization, larger proportions of respiratory distress syndrome, mechanical ventilation at birth, oxygen therapy after 48 hours of birth, oxygen dependency at 28 days, and continuous positive airway pressure support at 28 days compared to term infants during the neonatal period (P=0.000). Late-preterm infants and early-preterm infants were re-admitted more often than term infants during the first year of life (P=0.000). Also Late-preterm and early-preterm infants had increased chance of respiratory tract illness than term infants (P=0.001). CONCLUSION: In this study, we demonstrated that there are higher chances of respiratory morbidities in the late-preterm infants than the term infants either during the neonatal period or throughout the first year of life, although early-preterm infants showed greatest respiratory morbidities.

Differentiation of Rat Neural Stem Cells Following Transplantation in the Brain of Huntington's Disease Rat Model

Stem cells provide an important means for regenerative medicine due to the capacity to generate multiple types of differentiated cells and at the same time to maintain self-renewal. To identify the therapeutic effect of the transplantation of neural stem cells, differentiation and migration capacity of the neural stem cells that were isolated from E14 rat embryo and maintained in culture were examined after transplantation to the striatum of the quinolinic acid (QA)-induced Huntington's disease rat model. in vitro co-culture of the neural stem cells with the mixture of primary neurons and astrocytes promoted the maturation and the synapse formation of neuronal progenies of neural stem cells. Following the implantation, the neural stem cells survived, differentiated, and migrated in the damaged striatum region, exhibiting immunoreactivities against nestin, Tuj-1, GFAP, GAD(67) and synapsin 1 to a varying degree. These data provide clear evidence supporting that the neural stem cells isolated from the rat embryo and maintained in the primary culture have a multiple capacity to differentiate into neurons or glial cells both in vitro and in vivo.