Jeju Province Research Articles

Characteristics of Enterohaemorrhagic Escherichia coli in Jeju Province, Korea: a study of registry routes from 2017 to 2023

Enterohemorrhagic Escherichia coli (EHEC) produces Shiga toxin, which causes diarrhea, hemorrhagic colitis, and hemorrhagic uremic syndrome. The Korea Center for Disease Control and Prevention (KCDC) has designated EHEC as a legal infectious disease and has conducted laboratory surveillance. This study aimed to compare the demographic, epidemiological, clinical, and laboratory characteristics of EHEC cases in Jeju Province between August 2017 and November 2023, notified by two registry routes. The data were sourced from the integrated disease health and health management system managed by the KCDC. Cases reported due to experiencing gastrointestinal symptoms, or contacts of each case were defined as the “symptomatic” group. In contrast, cases with positive findings during a health checkup or laboratory surveillance were defined as the “screening” group. The symptomatic and screening groups had 35 and eight patients, respectively. There were significant differences in the age and seasonal distribution. The selection group was 20-59 years old in the main age distribution and registered evenly throughout the four seasons. In comparison, the symptomatic group was younger or older and not registered in the winter. These findings may be used to establish a more appropriate surveillance system for diarrheal outbreaks.

Monitoring and evaluation of provincial classical swine fever immunization implementation with an E2 subunit vaccine in Jeju Island, South Korea.

Accidental vaccination with a live attenuated low-virulence strain of Miyagi (LOM) vaccine led to the reemergence of classical swine fever virus (CSFV) in Jeju province, South Korea in 2014. To control the continual outbreaks of LOM-derived CSFV, the provincial government launched a provincial mass vaccination project using a CSF-E2 subunit vaccine. We conducted this study to assess the herd immunity level and outcomes of E2 vaccine-based immunization in breeding and growing herds on Jeju Island during 2020-2021. A large-scale vaccination trial using the Bayovac CSF-E2 vaccine investigated its efficacy in breeding and growing herds under farm application conditions (10 CSFV-affected and three CSFV-naïve swine farms). The level of herd immunity in each farm was classified into three (S1-S3) and six (G1-G6) profiles in breeding and growing herds, respectively. Immunity monitoring revealed a remarkable improvement in the herd immunity status in all farms. The majority (10/13) of farms, including CSFV-free farms, showed the S1G1 immunity profile in 2021, indicating the appropriate implementation of the advised vaccination regime. Moreover, there were significant decreases in Erns seropositivity from 100% to 50% and 25.9% to 4.3% at farm and pig levels, respectively. In particular, all farms were confirmed as CSFV free in the growing-finishing herds. Our large-scale trial demonstrated the effectiveness of the E2 subunit vaccine in establishing herd immunity stabilization and eliminating CSFV circulation in the affected farms and highlighted the need for a provincial vaccination policy to regain the CSF-free status on Jeju Island.

제주지역 시설재배에서 국내육성 ‘스위트골드’ 결과모지 전정시기에 따른 과실의 생장과 품질의 변화

제주지역 시설재배에서 국내육성 ‘스위트골드’ 결과모지 전정시기에 따른 과실의 생장과 품질의 변화

기후환경 변화와 관련된 ESG 요인이 제주지역 관광에 미치는 영향

기후환경 변화와 관련된 ESG 요인이 제주지역 관광에 미치는 영향

Trends of legionellosis reported in Jeju Province, Republic of Korea, 2015-2022.

The number of reported cases of Legionnaires' disease (LD) in the Republic of Korea surged nationally in 2016; however, in 2022, this number was higher in Jeju Province than the previous national peak. A descriptive epidemiological study was conducted to analyze trends in the incidence of reported LD cases in Jeju Island from 2015 to 2022. The data for this study were obtained from case reports submitted to the Korea Disease Control and Prevention Agency through its Disease and Health Integrated Management System. The selection criteria were cases or suspected cases of LD reported among Jeju residents between 2015 and 2022. The 95% confidence interval of the crude incidence rate was calculated using the Poisson distribution. Since 2020, the incidence rate of LD in Jeju has risen sharply, showing a statistically significant difference from the national incidence rate. A particular medical institution in Jeju reported a significant number of LD cases. Screening with the urine antigen test (UAT) also increased significantly. Our findings indicate that the rapid increase in cases of LD in Jeju Province since 2020 was due to the characteristics of medical-care use among Jeju residents, which were focused on a specific medical institution. According to their clinical practice guidelines, this medical institution conducted UATs to screen patients suspected of pneumonia.

Epidemiology of carbapenem-resistant Enterobacteriaceae in Jeju Province, Korea, using national surveillance data, 2018–2021

Carbapenem-resistant <i>Enterobacteriaceae</i> (CRE) infections have increased rapidly over the past decade and are recognized as a severe health threat in Korea and worldwide. This study aimed to identify the status and characteristics of CRE infection in Jeju province and provide important basic data for the prevention and management of CRE infection. A descriptive epidemiological analysis was performed on reported cases of CRE infection in Jeju Province between 2018 and 2021 using the integrated management system for disease, an infectious disease reporting system from the Korea Disease Control and Prevention Agency. The annual difference and distribution trends of CRE infection were analyzed using CRE isolates, carbapenemase-producing CREs (CP-CRE) and their genotypes, and the type of medical institution in Jeju Province. CRE infections steadily increased in Jeju from 2018 to 2021, and the proportion of CP-CRE among the CREs also showed a statistically significant increase each year. Among the CRE isolates, <i>Klebsiella pneumoniae</i> (KPC, 62.13%) was the most common, and among the CP-CRE genotypes, KPC (81.62%) showed the highest distribution and increased each year. As the distribution of CP-CRE in have increased over the past 4 years, measures to prevent the spread and outbreak of CRE infections are warranted. The results of this study are expected to be used as basic data for prevention and management of CRE infections in the province.

Prevalence of bovine viral diarrhea virus from Korean native cattle farms in Jeju

Bovine viral diarrhea virus (BVDV) is an RNA virus belonging to Pestivirus in the family Flaviviridae. BVDV has economic significance for the livestock industry because of its association with acute disease, fetal loss, and birth of persistently infected (PI) animals. This study aimed to investigate the BVDV infection rates in Korean native cattle farms in Jeju for further planning of a BVDV control program in the Jeju Province. BVDV antibodies and antigens were tested in 15,842 sera collected from 302 Korean native cattle herds between January 2014 and June 2017 using enzyme-linked immunosorbent assay (ELISA). Viral antigen was detected by reverse transcription-polymerase chain reaction from 60 sera that were antigen ELISA-positive. BVDV antibodies were found in 90.7% (274/302) herds and 61.1% (9,678/15,842) cows. BVDV antigens were found in 13.2% (40/302) herds and 0.4% (61/15,842) cows. The oldest animal group (> 8 years) exhibited the highest sero-positive rates (91%), while the youngest animal group (< 1 years) had the highest antigen positivity rates (0.52%). Of the 60 antigen-positive sera, BVDV types 1 and 2 were found in 36 and 12 sera, respectively. Additionally, six animals were considered to be PI as BVDV was continually detected in annual examination.

Epidemiological investigation of a food-borne outbreak in a kindergarten, Jeju Province, Korea.

On Monday, September 6, 2021, at a kindergarten in Jeju Province, a large number of children vomited and developed food poisoning symptoms, and this necessitated an epidemiological investigation. The team surveyed symptoms and food intake history of kindergarten children, teachers, and workers who ate lunch between September 2 (Thursday) and September 6 (Monday), excluding weekends. In addition to rectal swabs, environmental samples from preserved foods, cooking utensils, drinking water, and refrigerator handles were collected. Pulsed field gel electrophoresis (PFGE) for genetic fingerprint analysis was also performed. There were 19 cases among 176 subjects, which indicated an attack rate of 10.8%. The epidemic curve showed a unimodal shape, and the average incubation period was 2.6 hours. While no food was statistically significant in food intake history, the analysis of 35 rectal smear samples detected Bacillus cereus in 7 children, 4 teachers, and 1 cooking staff. Enterotoxins were also detected in 12 samples. Out of 38 environmental samples, B. cereus and enterotoxins were detected in the morning snack cereal, lunch bean sprouts, and afternoon snack steamed potatoes on Monday, September 6th. The result of the PFGE test on 10 isolates of B. cereus showed that there was no genetic homology. Our results indicated that this outbreak was simultaneously caused by various strains of B. cereus from the environment.

Trends in incidences of newly notified tuberculosis in Jeju Province, Korea, 2017-2021

In 2021, the incidence of newly notified tuberculosis in Jeju Province decreased by 23.0% compared to that in the previous year. This was the largest decline among the 18 municipalities studied. This study aimed to examine trends in the incidence of tuberculosis among different age and sex groups in Jeju Province between 2017 and 2021. This study observed the number of new cases in the annual report from 2017 to 2021, published by the Jeju Center for Infectious Diseases Control and Prevention. The average annual percentage change (AAPC; %) was calculated to determine the trend in crude incidence rates over the past 5 years by sex and age. While a <i>P</i>-value of <0.1 was considered marginally significant, a <i>P</i>-value of <0.05 was considered statistically significant. The AAPC of all age groups in Jeju Province had negative values. In men, there was a statistically significant decrease in ages 30-34, 40-44, 45-49, and 50-54 years and a marginally significant decrease in ages 35-59, 55-59, 60-64, 65-69, 75-79, and ≥80 years. In women, a statistically significant decrease was observed among patients aged 30-34, 35-39, and ≥80 years, and a marginally significant decrease was observed among patients aged 45-49, 50-54, 60-64, 65-69, and 75-79 years. A statistically significant decrease in tuberculosis was observed among patients in their 30s and 40s, and elderly patients aged ≥80 years comprised the group vulnerable to tuberculosis. Based on these findings, tuberculosis prevention and screening programs conducted in Jeju Province were effective.

Residents’ perceptions of household food waste during the COVID-19 outbreak in Korea

Analyzing household food waste data at the global or national level remains a challenge, especially owing to lack of statistical systems and socio-cultural differences. This study determined the factors affecting the intention of households to reduce food waste on Jeju Island and on the Korean mainland. Socio-demographic factors significantly influence household food waste generation. Therefore, studies are often conducted depending on data availability in the corresponding regions. Based on national data and the theory of planned behavior, this study analyzed data using PLS-SEM (Partial Least Squares Structural Equation Modeling) to test the influence of multiple determinants and parameters on dependent variables and investigated the awareness of household food waste in Korea, focusing on Jeju Province, Korea’s largest tourist destination. A survey of 508 local residents established that all factors evaluated in this study, except for risk concerns due to COVID-19, were statistically significant. Among the three antecedents of age, income, and family size, age significantly affected all mediators, directly affecting behavioral intentions. The results are consistent with those of preceding research on the effects of socio-demographic drivers on household food waste generation. The results also indicate that in Korea, where the COVID-19 infection level is lower than that in other countries, residents did not change their food purchasing and waste production patterns. However, a multi-group analysis revealed that the risk concerns caused by COVID-19 differed between residents of Jeju Island and mainland Korea. Overcoming the vulnerability of waste management, including food dumping, is mandatory for locals and tourists on Jeju Island.

Useful Plants from the Wild to Home Gardens: An Analysis of Home Garden Ethnobotany in Contexts of Habitat Conversion and Land Use Change in Jeju, South Korea

Home gardens are often the most agrobiodiverse sites in the anthropogenic environment, a space where crops and other useful plants are often transplanted from other components of the landscape. This study investigates the plant composition of home gardens and their usefulness in 12 small towns and villages—with three of these chosen as the focus for in-depth research—situated in the Jeju province of South Korea. The goal of the research is to explore their roles in local ethnobotany in the context of habitat conversion and land use change. The 131 home gardens surveyed in these villages yielded 164 species- and variety-level plant taxa (52 wild, 109 domesticated, and 3 introduced), of which 95 were useful plant taxa (39 wild, 55 domesticated, and 1 introduced). Use of home garden plants was predominantly for food and medicinal purposes. Home garden plant usefulness was more multi-functional and thus more versatile than practices associated with these plants in non-garden habitats. Plant diversity in home gardens was supported by the presence of nearby forest and grassland areas. Interview data indicate that plant users were motivated to transplant wild plants into their home gardens in order to secure a consistent supply, given decreases in wild plant populations in the last 15–20 years. The loss and overharvesting of forests and other wild plant habitats have caused the decrease in these plant populations. Underlying drivers of the habitat conversion and land use change influencing increased wild plant transplants to home gardens are local livelihood and lifestyle changes, including the earlier expansion of commercial agriculture beginning in the late 1960s and the accelerated growth of tourism since 2000.

목표중심 자기조절과 선제적행동 관계에서 직무효능감과 회복탄력성의 다중 매개효과

The paradigm shift on employees from the passive to the active in modern organizations stresses on roles of personal initiative and self-regulation is at the edge of it. The purposes of the current study in this context were tested the main effect of goal-focused self-regulation as an independent variable on initiative behaviors and the mediational process via job-efficacy and resilience as dual mediators in this relationship. The data collection carried out from 400 employees who have worked at private companies and government offices located in Jeju Province. In addition, temporal separation method with a week gab toward same participants was applied. 355 sets of questionnaires were collected and 298 sets among them were used for analysis except for 57 sets with SPSS Macro program. The goal-focused self-regulation had positive effects on job-efficacy, resilience, and initiative behavior respectively as expected. In terms of mediating effects on job-efficacy and resilience, job-efficacy mediated the relationship between goal-focused self-regulation on initiative behavior but no significance in the path of resilience. These results which highlight a positive role of the goal-focused self-regulation enable to contribute to facilitate researcher’s interest of it and to show distinctive psychological process in the links between goal-focused self-regulation and initiative behaviors.

Utility of ultra-rapid real-time PCR for detection and prevalence of Rickettsia spp. in ticks

BackgroundRickettsia spp. are important tick-borne pathogens that cause various human and animal diseases worldwide. A tool for rapid and accurate detection of the pathogens from its vectors is necessary for prevention of Rickettsioses propagation in humans and animals, which are infested by ticks. Therefore, this study was conducted to evaluate a molecular tool, ultra-rapid real-time PCR (UR-qPCR), for rapid and accurate detection of Rickettsia spp. from 5644 ticks in 408 pools collected from livestock and their surrounding environments in Gangwon and Jeju province in South Korea.ResultsThe UR-qPCR of Rickettsia DNA showed a limit of detection of 2.72 × 101 copies of Rickettsia DNA and no cross reaction with other tick-borne pathogens, namely Anaplasma phagocytophilum, Ehrlichia chaffeensis, E. canis, Toxoplasma gondii, and Borrelia burgdorferi. In addition, the PCR assay also showed possibility of various Rickettsia species detection including R. monacensis, “Candidatus R. longicornii”, R. japonica, R. roultii, and R. tamurae. The collected ticks were identified with major species belonged to Haemaphysalis longicornis (81.62%), followed by H. flava (15.19%), and Ixodes nipponensis (3.19%). Rickettsia detection from tick samples using the UR-qPCR showed that the minimum infection rate (MIR) of Rickettsia in collected ticks was 1.24‰ and that all positive pools contained H. longicornis, equal to the MIR of 1.39‰ of this species. Additionally, MIR of Rickettsia spp. detected in ticks collected in Gangwon and Jeju was 1.53‰ and 0.84‰, respectively. Furthermore, the sequencing results of the 17 kDa protein antigen gene and ompA gene showed that Rickettsia spp. sequences from all pools were related to “Candidatus R. longicornii” and “Candidatus R. jingxinensis”.ConclusionsThe UR-qPCR system was demonstrated to be useful tool for accurate and rapid detection of Rickettsia from its vector, ixodid ticks, within 20 min. The data on Rickettsia spp. in ticks detected in this study provide useful information on the distribution of Rickettsia in previously unstudied Korean provinces, which are important for the prevention and control of the spread of rickettsioses in both animals and humans in the country.

Clinical training and career planning of dental hygienist students in Jeju province

Clinical training and career planning of dental hygienist students in Jeju province

대인관계기술과 경력만족 관계에서 자기관리의 매개효과와 성별의 조절된 매개효과

Though the paradigm movement of career from organization-focus to individual-focus highlights the roles of individual, it is still necessary for scholars to consider the function of personal resources for career development in organizations regarded as a social interactive field. This study set up a few variables; interpersonal skill described on effective personal resource in social context, self-management focused on voluntary regulation of individual behavior, career satisfaction represented as a positive evaluation on career and gender as a remarkable conditional variables in awareness of career outcome. We tested two types of main effects, mediating effects, and conditional indirect effects empirically. The data collected from 335 employees working at service and state-owned companies in Jeju province. We used SPSS Macro to test main effects, mediating effects with model 4, and moderated mediation effects with model 7. Interpersonal skill were positively related to self-management and career satisfaction respectively. In the mediation process, self-management were partially mediated the links between interpersonal skill and career satisfaction, in addition, the conditional indirect effect of gender in the path of interpersonal skill on career satisfaction via self-management was significant. These results indicated that a personal resource facilitates career development and self-regulation activities and it enable to be a main driver in the psychological mechanism in the basis of self-regulation. In addition, this finding supplies a meaningful implication of gender perception gap in the impact of personal resources for career development.

Hierarchical landform delineation for the habitats of biological communities on the Korean Peninsula.

Landforms determine the locations of particular biological communities based on their components and spatial positions. This study hierarchically classified the topographic spaces serving as habitats for biological communities in the Korean Peninsula and established the habitat types that occur on the classified landform types. We classified landform types by applying cell-based modeling, map algebra, and spatial query techniques to spatial data, including digital elevation model (DEM), Sentinel 2 image, land use, and field survey data to model their ecological characteristics. Landforms were classified into four categories (designated Category 1 through 4) according to their spatial scale based on topographical characteristics such as mountains, plains, alluvial landforms, coastal landforms, islands, and special areas (Baekdudaegan, DMZ), which are found throughout the Korean Peninsula. The landforms of the Korean Peninsula were classified into 47 subcategories in Category 1, 16 in Category 2, 36 in Category 3, and 63 in Category 4. There were 62 main types of habitats that were classified based on their topographic spatial units, and there were 437 types of sub-habitats, for which soil weathering, biodiversity, and geodiversity were combined with the main habitat types. When factor analysis was conducted for the environmental factors used to determine the main and sub-habitats, the first primary components were temperature-related factors, followed by biodiversity, geodiversity, aspect, and slope. When the indicator species were analyzed by habitat type, indicator species diversity was high in Jeju Province, Gangwon Province, and Gaema Plateau. Based on these results, landform elements for species habit conservation were assigned conservation values and classified into (I) absolute conservation areas, (II) transition areas, and (III) areas for coexistence with humans. Topographic spaces are being degraded as biological habitats as a result of climate change and human development; our proposed classifications can be applied to the conservation of landforms and biodiversity.

Awareness of national health insurance-covered dental care of adults in Jeju province

Awareness of national health insurance-covered dental care of adults in Jeju province

A Salmonella-related foodborne outbreak in a snack bar in Jeju Province: an epidemiological investigation

Many people reported suspected food poisoning after consuming food at the same snack bar on June 18, 2020. Thus, an in-depth epidemiological investigation was conducted to identify the infectious agent and establish additional food poisoning prevention measures. The study included people who reported to the local public health center after June 18 with acute gastroenteritis symptoms within 4 days of consuming food from the snack bar. The onset of symptoms and food items consumed by individuals were then investigated via phone calls and on-site visits. Afterward, the infectious agent was identified from human samples (stool or rectal swab) of four restaurant employees and 89 people and from environmental samples (materials, cooking utensils, and water). The analysis revealed that the incubation period ranged from 2 hours to 92 hours, with a median and mode of 16 hours and 12 hours, respectively. Moreover, the epidemic curve had a unimodal shape because of common exposure, which reached its peak on June 18. After monitoring for 8 days, which is more than twice the maximum incubation period of 92 hours, the end of the epidemic was declared on June 28 as no additional cases were reported. Analysis of human and environmental samples revealed Salmonella bareilly of the pulsed-field gel electrophoresis pulsotype SAPX01.017 as the causative agent. Therefore, it was concluded that the food poisoning outbreak was caused by S. bareilly.

Molecular detection and identification of Culex flavivirus in mosquito species from Jeju, Republic of Korea

BackgroundMosquito-borne flaviviruses are prime pathogens and have been a major hazard to humans and animals. They comprise several arthropod-borne viruses, including dengue virus, yellow fever virus, Japanese encephalitis virus, and West Nile virus. Culex flavivirus (CxFV) is a member of the insect-specific flavivirus (ISF) group belonging to the genus Flavivirus, which is widely distributed in a variety of mosquito populations.MethodsViral nucleic acid was extracted from adult mosquito pools and subjected to reverse transcriptase nested polymerase chain reaction (PCR) using target-specific primers for detecting CxFV nonstructural protein 5 (NS5). The PCR-positive samples were then sequenced, and a phylogenetic tree was constructed, including reference sequences obtained from GenBank.Results21 pools, belonging to Culex pipiens pallens (Cx. p. pallens) were found to be positive for the CxFV RNA sequence, with a minimum infection rate of 14.5/1000 mosquitoes. The phylogenetic analysis of the NS5 protein sequences indicated that the detected sequences were closely related to strains identified in China, with 95–98% sequence similarities.ConclusionOur findings highlight the presence of CxFV in Cx. p. pallens mosquito species in Jeju province, Republic of Korea. This is the first study reporting the prevalence of CxFV in Culex Pipiens (Cx. pipiens) host in the Jeju province, which can create possible interaction with other flaviviruses causing human and animal diseases. Although, mosquito-borne disease causing viruses were not identified properly, more detailed surveillance and investigation of both the host and viruses are essential to understand the prevalence, evolutionary relationship and genetic characteristic with other species.

Sources of Infection Among Confirmed Cases of COVID-19 in Jeju Province, Korea.

ObjectivesJeju Province in Korea reported 627 coronavirus disease 2019 (COVID-19) cases between January 20, 2020, and March 31, 2021. This study analyzed the sources of infection among confirmed cases in Jeju Province, a self-governed island.MethodsThe sources of infection were broadly categorized as follows: (1) infections from overseas (confirmed patients who reported travel overseas or contact with overseas travelers); (2) infections from outside Jeju Province (confirmed patients who had visited other provinces or had contact with individuals who had traveled to other provinces in Korea); and (3) unknown sources of infection (confirmed patients who were infected following contact with an infected person whose source of infection was unknown). The chi-square test was used to analyze the differences in the distributions of related variables for each source of infection.ResultsOf the 627 confirmed cases, 38 (6.1%) were infections from overseas sources, 199 (31.7%) were from outside of Jeju Province, and 390 (62.2%) were from unknown sources. Jeju Province had no cases with an unknown source of infection during the first and second waves of the nationwide outbreak.ConclusionsInfections from overseas sources could be blocked from spreading to local communities in Jeju Province by conducting screening at the airport, along with the preemptive suspension of visa-free entry. In addition, considering the scale of the nationwide outbreak, measures must be established to delay outbreaks from unknown sources of infection caused by sources outside Jeju Province.