Outbreak In South Korea Research Articles

First Trial of a Novel Caseous Lymphadenitis Inactivated Vaccine in South Korea: Experimental Evaluation across Various Animal Models.

Caseous lymphadenitis (CLA) is a chronic and subclinical bacterial disease of ruminants caused by Corynebacterium pseudotuberculosis (C. pseudotuberculosis) infection. Until 2014, there were no reports of CLA outbreaks in South Korea; however, the prevalence of CLA cases has steadily increased. In this study, we used recently obtained field isolates to develop the first inactivated CLA vaccine in South Korea and evaluated it in various animal models. The inactivated vaccine was evaluated for virulence and effectiveness. Mice were tested for virulence and immunization challenges, and guinea pigs and Korean Native Black Goats (KNBGs) evaluated various vaccine concentrations to determine the optimal dose and effectiveness. In the case of KNBGs, clinical symptoms were not observed after vaccination. In addition, CLA-specific IgG was detected at a significantly (p < 0.05) high level and was maintained. In histopathological evaluations, inflammation was predominantly observed in the prefemoral lymph nodes in the non-vaccinated+CHAL group. The genetic diversity of C. pseudotuberculosis, which has become widespread in South Korea, is less than 0.5% our vaccine is expected to prevent infection by a wide range of strains effectively. In summary, our CLA vaccine can potentially prevent CLA and foster the growth of South Korea's domestic KNBG industry.

Trends of fear and anger on YouTube during the initial stage of the COVID-19 outbreak in South Korea

BackgroundThe COVID-19 pandemic has been the most widespread and threatening health crisis experienced by the Korean society. Faced with an unprecedented threat to survival, society has been gripped by social fear and anger, questioning the culpability of this pandemic. This study explored the correlation between social cognitions and negative emotions and their changes in response to the severe events stemming from the COVID-19 pandemic in South Korea.MethodsThe analysis was based on a cognitive-emotional model that links fear and anger to the social causes that trigger them and used discursive content from comments posted on YouTube’s COVID-19-related videos. A total of 182,915 comments from 1,200 videos were collected between January and December 2020. We performed data analyses and visualizations using R, Netminer 4.0, and Gephi software and calculated Pearson’s correlation coefficients between emotions.ResultsYouTube videos were analyzed for keywords indicating cognitive assessments of major events related to COVID-19 and keywords indicating negative emotions. Eight topics were identified through topic modeling: causes and risks, perceptions of China, media and information, infection prevention rules, economic activity, school and infection, political leaders, and religion, politics, and infection. The correlation coefficient between fear and anger was 0.462 (p < .001), indicating a moderate linear relationship between the two emotions. Fear was the highest from January to March in the first year of the COVID-19 outbreak, while anger occurred before and after the outbreak, with fluctuations in both emotions during this period.ConclusionsThis study confirmed that social cognitions and negative emotions are intertwined in response to major events related to the COVID-19 pandemic, with each emotion varying individually rather than being ambiguously mixed. These findings could aid in developing social cognition-emotion-based public health strategies through education and communication during future pandemic outbreaks.

Using isometric log-ratio in compositional data analysis for developing a groundwater pollution index

This study introduces a novel groundwater pollution index (GPI) formulated through compositional data analysis (CoDa) and robust principal component analysis (RPCA) to enhance groundwater quality assessment. Using groundwater quality monitoring data from sites impacted by the 2010–2011 foot-and-mouth disease outbreak in South Korea, CoDa uncovers critical hydrochemical differences between leachate-influenced and background groundwater. The GPI was developed by selecting key subcompositional parts (NH4+-N, Cl-, and NO3--N) using RPCA, performing the isometric log-ratio (ILR) transformation, and normalizing the results to environmental standards, thereby providing a more precise and accurate assessment of pollution. Validated against government criteria, the GPI has shown its potential as an alternative assessment tool, with its reliability confirmed by receiver operating characteristic curve analysis. This study highlights the essential role of CoDa, especially the ILR -transformation, in overcoming the limitations of traditional statistical methods that often neglect the relative nature of hydrochemical data. Our results emphasize the utility of the GPI in significantly advancing groundwater quality monitoring and management by addressing a methodological gap in the quantitative assessment of groundwater pollution.

The effectiveness of intervention measures on MERS-CoV transmission by using the contact networks reconstructed from link prediction data.

Mitigating the spread of infectious diseases is of paramount concern for societal safety, necessitating the development of effective intervention measures. Epidemic simulation is widely used to evaluate the efficacy of such measures, but realistic simulation environments are crucial for meaningful insights. Despite the common use of contact-tracing data to construct realistic networks, they have inherent limitations. This study explores reconstructing simulation networks using link prediction methods as an alternative approach. The primary objective of this study is to assess the effectiveness of intervention measures on the reconstructed network, focusing on the 2015 MERS-CoV outbreak in South Korea. Contact-tracing data were acquired, and simulation networks were reconstructed using the graph autoencoder (GAE)-based link prediction method. A scale-free (SF) network was employed for comparison purposes. Epidemic simulations were conducted to evaluate three intervention strategies: Mass Quarantine (MQ), Isolation, and Isolation combined with Acquaintance Quarantine (AQ + Isolation). Simulation results showed that AQ + Isolation was the most effective intervention on the GAE network, resulting in consistent epidemic curves due to high clustering coefficients. Conversely, MQ and AQ + Isolation were highly effective on the SF network, attributed to its low clustering coefficient and intervention sensitivity. Isolation alone exhibited reduced effectiveness. These findings emphasize the significant impact of network structure on intervention outcomes and suggest a potential overestimation of effectiveness in SF networks. Additionally, they highlight the complementary use of link prediction methods. This innovative methodology provides inspiration for enhancing simulation environments in future endeavors. It also offers valuable insights for informing public health decision-making processes, emphasizing the importance of realistic simulation environments and the potential of link prediction methods.

Characterization of Salmonella species from poultry slaughterhouses in South Korea: carry-over transmission of Salmonella Thompson ST292 in slaughtering process.

Salmonella outbreaks linked to poultry meat have been reported continuously worldwide. Therefore, Salmonella contamination of poultry meats in slaughterhouses is one of the critical control points for reducing disease outbreaks in humans. This study examined the carry-over contamination of Salmonella species through the entire slaughtering process in South Korea. From 2018 to 2019, 1,097 samples were collected from the nine slaughterhouses distributed nationwide. One hundred and seventeen isolates of Salmonella species were identified using the invA gene-specific polymerase chain reaction, as described previously. The serotype, phylogeny, and antimicrobial resistance of isolates were examined. Among the 117 isolates, 93 were serotyped into Salmonella Mbandaka (n = 36 isolates, 30.8%), Salmonella Thompson (n = 33, 28.2%), and Salmonella Infantis (n = 24, 20.5%). Interestingly, allelic profiling showed that all S. Mbandaka isolates belonged to the lineage of the sequence type (ST) 413, whereas all S. Thompson isolates were ST292. Moreover, almost all S. Thompson isolates (97.0%, 32/33 isolates) belonging to ST292 were multidrug-resistant and possessed the major virulence genes whose products are required for full virulence. Both serotypes were distributed widely throughout the slaughtering process. Pulsed-field gel electrophoretic analysis demonstrated that seven S. Infantis showed 100% identities in their phylogenetic relatedness, indicating that they were sequentially transmitted along the slaughtering processes. This study provides more evidence of the carry-over transmission of Salmonella species during the slaughtering processes. ST292 S. Thompson is a potential pathogenic clone of Salmonella species possibly associated with foodborne outbreaks in South Korea.

Determination of Optimal Antigen Yield and Virus Inactivation Conditions for the Production of the Candidate Foot-and-Mouth Disease Recombinant Vaccine Strain Asia1 Shamir-R in a Bioreactor.

Since the foot-and-mouth disease (FMD) outbreak in South Korea in 2010-2011, vaccination policies utilizing inactivated FMD vaccines composed of types O and A have been implemented nationwide. However, because type Asia1 occurred in North Korea in 2007 and intermittently in neighboring countries, the risk of type Asia1 introduction cannot be ruled out. This study evaluated the antigen yield and viral inactivation kinetics of the recombinant Asia1 Shamir vaccine strain (Asia1 Shamir-R). When Asia1 Shamir-R was proliferated in shaking flasks (1 L), a 2 L bioreactor (1 L), and a wave bioreactor (25 L), the antigen yields were 7.5 μg/mL, 5.2 μg/mL, and 3.8 μg/mL, respectively. The optimal FMDV inactivation conditions were 2 mM BEI at 26 °C and 1.0 mM BEI at 37 °C. There was no antigen loss due to BEI treatment, and only a decrease in antigen levels was observed during storage. The sera from pigs immunized with antigen derived from a bioreactor exhibited a neutralizing antibody titer of approximately 1/1000 against Asia1 Shamir and Asia1/MOG/05 viruses; therefore, Asia1 Shamir-R is expected to provide sufficient protection against both viruses. If an FMD vaccine production facility is established, this Asia1 Shamir-R can be employed for domestic antigen banks in South Korea.

Evolution and Spread of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus in Wild Birds, South Korea, 2022-2023.

During October 2022-March 2023, highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b virus caused outbreaks in South Korea, including 174 cases in wild birds. To understand the origin and role of wild birds in the evolution and spread of HPAI viruses, we sequenced 113 HPAI isolates from wild birds and performed phylogenetic analysis. We identified 16 different genotypes, indicating extensive genetic reassortment with viruses in wild birds. Phylodynamic analysis showed that the viruses were most likely introduced to the southern Gyeonggi-do/northern Chungcheongnam-do area through whooper swans (Cygnus cygnus) and spread southward. Cross-species transmission occurred between various wild bird species, including waterfowl and raptors, resulting in the persistence of HPAI in wild bird populations and further geographic spread as these birds migrated throughout South Korea. Enhanced genomic surveillance was an integral part of the HPAI outbreak response, aiding in timely understanding of the origin, evolution, and spread of the virus.

654. Changing trends of molecular characteristics and antimicrobial susceptibility of hypervirulent Klebsiella pneumoniae in community-acquired liver abscess before and after COVID-19 outbreak in South Korea

Abstract Background Hypervirulent Klebsiella pneumoniae (K. pneumoniae, hvKP) causes invasive infections, usually community-acquired liver abscess. In this study, we aimed to compare the molecular characteristics and antimicrobial susceptibility of hvKP in community-acquired liver abscess over times, especially before and after COVID-19 outbreak. Methods This study was performed on K. pneumoniae isolates of community-acquired liver abscess collected from Keimyung University Dongsan Hospital from 2014-2015 and 2020-2021. Clinical and microbiologic data were collected from medical records. Capsular serotypes and virulence factors were identified by polymerase chain reaction using specific primers. Results A total 79 patients were analyzed, 39 (49.4%) of 2014-2015 and 40 (50.6%) of 2020-2021. Capsular serotype K1 (61.5% vs. 62.5%) and K2 (25.6% vs. 30.0%) were no significant differences between the two periods. In virulence factors, IutA (82.1% vs. 97.5%) was significantly increased in 2020-2021 compared to 2014-2015 (p=0.028). RmpA (84.6% vs. 90.0%), kfu (61.5% vs. 70.0%), allS (56.4% vs. 67.5%) were showed no significant changes between two periods. Antimicrobial susceptibility of ciprofloxacin (100.0% vs. 95.0%), ceftriaxone (97.4% vs. 89.7%), and imipenem (100.0% vs. 97.5%) were no significant differences between the two periods.Table 1.Molecular characteristics of hypervirulent Klebsiella pneumoniae in community-acquired liver abscess Conclusion In liver abscess, the virulence factors showed a tendency to increase during the study period such as IutA, but the limitation is that there were small numbers of isolates included in this study. Further studies with larger number of isolates will be required to findout the changing characteristics of hvKP over times. Disclosures All Authors: No reported disclosures

Predicting Disparity between ASF-Managed Areas and Wild Boar Habitats: A Case of South Korea.

African swine fever (ASF) is a highly contagious viral disease affecting both domestic and wild boars. Since its first outbreak in South Korea in 2019, substantial efforts have been made to prevent ASF transmission by reducing the wild boar population and eliminating infected carcasses; however, the persistence of ASF transmission has posed challenges to these efforts. To improve ASF management strategies, the limitations of current management strategies must be identified by considering disparities between wild boar habitats and ASF-managed areas with environmental and anthropogenic characteristics of wild boars and their management strategies. Here, ensemble species distribution models were used to estimate wild boar habitats and potential ASF-managed areas, with elevation, distance to urban areas, and Normalized Difference Vegetation Index as important variables. Binary maps of wild boar habitats and potential ASF-managed areas were generated using the maxSSS as the threshold criterion. Disparity areas of ASF management were identified by overlying regions evaluated as wild boar habitats with those not classified as ASF-managed areas. Dense forests near urban regions like Chungcheongbuk-do, Gyeongsangbuk-do, and Gyeongsangnam-do were evaluated as disparity areas having high risk of ASF transmission. These findings hold significant potential for refining ASF management strategies and establishing proactive control measures.

COVID-19 infection and efficacy of vaccination in patients with rheumatic diseases during Omicron outbreak in South Korea: a prospective cohort study

ObjectivesThis study aims to investigate COVID-19 epidemiological data in patients with autoimmune inflammatory rheumatic diseases (AIRDs) during Omicron wave and to identify clinical factors associated with infection, including COVID-19 vaccination.MethodsThis...

Challenging treatment of food wastes for cleaner production after the African swine fever outbreak in South Korea

Food waste is a growing global concern, necessitating effective treatment solutions. South Korea stands out with over 90% of its food waste being recycled, driven by robust resource circulation policies. Across Asia, anaerobic digestion processes are favored for food waste treatment due to their economic and environmental advantages. The South Korean Government aims to expand anaerobic digestion to ensure stable organic waste treatment. However, the 2019 outbreak of African swine fever (ASF) in pig farms led to the cessation of wet feed production, comprising 22% of total feed. This has increased the pressure on alternative recycling methods. The handling of food waste leachate, generating around 1080 t/d during treatment, has become a concern due to the discontinuation of wet feed production. The objective of this study is to develop a food waste policy. It begins by assessing food waste and leachate generation through field surveys of 346 treatment facilities engaged in pretreatment, feeding, composting, and biogasification. To mitigate the impact of ASF outbreaks in the short term, a proposed solution involves diverting food waste leachate to existing sewage treatment plant digesters during non-injection weekends and other off-peak times. This measure aims to completely treat the maximum discharge of approximately 2000 t/d during the peak summer ASF outbreak periods. For the long term, a strategy involving anaerobic digestion is suggested in response to the gradual reduction in wet or dry feed production, along with composting, the conventional treatment method. This transition not only curbs greenhouse gas emissions but also enhances biogas production, a renewable energy source. These efforts align with the Korean Green New Deal’s goal of achieving a 20% share of renewable energy by 2030.

The Politics of Quarantine: The Political Implications of Negative Social Affects in the Early Stage of COVID-19 in South Korea

We analyze the interrelationships between quarantine-related events and negative social affects during COVID-19 in South Korea. We explain the impact of these relationships on the political nature of quarantine. We conducted a discourse analysis of YouTube comments posted on COVID-19-related videos during 2020. We analyzed these affects and their social and cognitive triggers using cognition-emotion theory and affect theory. Contingent COVID-19 outbreaks in South Korea and ambiguous information contributed to fear and anger. Social disgust combined with anger as mass infection events occurred over time, influencing the attitudes of South Korean citizens who support the country’s social distancing policy. We find that social disgust realized through exclusion and purification is associated with the politics of quarantine. Consequently, we show that the political disgust surrounding quarantine was embedded within social disgust. This study paves the path for further research on the governmentality of affects and mobility in the context of epidemics.

Implication of close contact testing in eliminating an epidemic: Application to COVID-19 epidemic in South Korea and New York City

After the first wave of the coronavirus epidemic, temporary stability in the disease spread dynamics was observed in many regions. This behavior can potentially be attributed to the measures implemented to contain the spread, particularly close contact testing. We propose a deterministic mathematical model that simulates the dynamic spread of the disease while considering the actions of the public health system. The developed model achieves a non-forced balance in daily confirmed cases, reproducing the observed epidemic behavior during the COVID-19 outbreak in South Korea and New York City. Our finding indicated that, although the quasi-steady state behavior can only be attained within a certain range of model parameters, an increase in the health system&amp;rsquo;s interventions does not eliminate the epidemic. We conclude that the observed stationary state of daily COVID-19 cases does not result from setting the basic reproductive number to one. Instead, it emerges as a natural consequence of the policies implemented by authorities to mitigate its spread.

The Impact of Social Media on Preventive Behavior During the COVID-19 Outbreak in South Korea: The Roles of Social Norms and Self-Efficacy.

Social media are important channels to propagate health information and influence preventive behavior during a public health crisis, as witnessed during the coronavirus pandemic (COVID-19). This study explored the association between social media use and preventive behavior during the outbreak of COVID-19 in South Korea. Using the national survey data (N = 1,500), the study examined the mediating role of social norms in the association between social media use for news and information about COVID-19 and preventive behavior. In addition, the study tested the moderating effect of self-efficacy on the mediating path of social media use for preventive behavior via social norms. Conducting a moderated mediation analysis method, this study found that social norms mediated the relationship between social media use and preventive behavior (b = 0.046). Moreover, the study revealed that the indirect relationship between social media use and preventive behavior through social norms becomes stronger as an individual's level of self-efficacy decreases (low: b = 0.044, middle: b = 0.036, and high: b = 0.030). The study provides empirical evidence of the beneficial impact of social media use on preventive behavior. The findings of the study recommend promoting messages on social norms through social media for facilitating preventive behavior.

Whole-genome sequencing of Listeria monocytogenes isolated from the first listeriosis foodborne outbreak in South Korea.

Listeria monocytogenes is a foodborne pathogen that causes listeriosis in humans with severe symptoms. In South Korea, listeriosis had only been reported sporadically among hospitalized patients until the first foodborne outbreak occurred in 2018. In this study, a L. monocytogenes strain responsible for this outbreak (FSCNU0110) was characterized via whole genome sequencing and compared with publicly available L. monocytogenes genomes of the same clonal complex (CC). Strain FSCNU0110 belonged to multilocus sequence typing (MLST)-based sequence type 224 and CC224, and core genome MLST-based sublineage 6,178. The strain harbored tetracycline resistance gene tetM, four other antibiotic resistance genes, and 64 virulence genes, including Listeria pathogenicity island 1 (LIPI-1) and LIPI-3. Interestingly, llsX in LIPI-3 exhibited a characteristic SNP (deletion of A in position 4, resulting in a premature stop codon) that was missing among all CC224 strains isolated overseas but was conserved among those from South Korea. In addition, the tetM gene was also detected only in a subset of CC224 strains from South Korea. These findings will provide an essential basis for assessing the characteristics of CC224 strains in South Korea that have shown a potential to cause listeriosis outbreaks.

Health risks of pest control and disinfection workers after the COVID-19 outbreak in South Korea

The exposure patterns of pest control and disinfection workers have changed after the coronavirus disease 2019 (COVID-19) outbreak, but the health risks of chemical exposure have not been assessed. We identified these workers' chemical exposure patterns and risks before and after the COVID-19 outbreak. We used data conducted between 2018 (pre-pandemic) and 2021 (post-pandemic) from three-year cross-sectional surveys on pest control and disinfection workers. Inhalation and dermal exposure concentrations were estimated using equations based on a biocidal product risk assessment model from the Korean National Institute of Environmental Research. The non-carcinogenic and carcinogenic risks of chemicals were calculated using the United States Environmental Protection Agency risk assessment model. We found that the annual work frequency (50th percentile) of foggers using disinfectants increased the most among all the work types, from 140 uses/year to 176 uses/year after the COVID-19 outbreak. Moreover, all chemicals' non-carcinogenic and carcinogenic risks increased regardless of exposure routes. In the worst scenario (95th percentile), the margin of exposure for citric acid, benzethonium chloride, benzyl-C12-16-alkyldimethyl chlorides, and sodium chlorite of inhalation exposure, and isopropyl alcohol and benzyl-C12-16-alkyldimethyl chlorides of dermal exposure were acceptable (>100) before the COVID-19 outbreak but became unacceptable (<100) after the COVID-19 outbreak. Carcinogenic risks of dichlorvos from inhalation and dermal exposure were above acceptable levels (>10−6) before and after the COVID-19 outbreak but comparatively high after the COVID-19 outbreak. Additionally, significantly more workers experienced health symptoms after the COVID-19 outbreak (p<0.05), with the most common being muscle lethargy (31%), skin/face stinging (28.7%), and breath shortness/neck pain (24.1%).

The changes in smoking stigmatization during the COVID-19 pandemic

ObjectivesThis study aimed to analyze the changes in smoking stigmatization in relation to an individual's smoking status after the COVID-19 outbreak. Study designA 2 (before vs. after COVID-19) X 2 (smoking status: smoker vs. non-smoker) factorial design was developed. MethodsTwo national surveys were conducted, one each before (between January 7th and 15th, 2020) and after (between January 26th and February 18th, 2021) the COVID-19 outbreak in South Korea. A total of 7296 representative adult responses were finalized. Respondents were categorized into two groups: non-smokers and smokers. Smoking stigma was measured in two ways: social and personal. ResultsIn general, smoking stigmatization intensified after the COVID-19 outbreak. However, there was a discrepancy in responses based on smoking status—non-smokers exhibited a heightened negative stigma toward smokers, whereas smokers had generous perspectives about themselves. ConclusionsThe health-oriented environment generated by the response to COVID-19 is leading to increased stigmatization of smokers who pose a risk to public health. However, the discrepancy between smokers and non-smokers shows that social efforts are required to alter smokers’ generous views about themselves and to persuade them to cease smoking.

Research on Korean Translation in the Context of Epidemic Prevention and Control

An emergency like COVID-19 requires a theoretical framework for policy implementation that involves public and private sector collaborations. After policy failures, new institutions have formed that trigger PPP's later, allowing the incumbent administration to continue in office longer. It focuses on novel approaches to dealing with pandemics. The present administration put these rules in place to keep COVID-19 under control. When it comes to Real Time - polymerase chain reaction (RT-PCR) testing, South Korea's government and corporations partnered to swiftly raise the quantity of testing in the country. Models of policy change are shown to be dynamic, cyclical, and recursive. During the COVID-19 outbreak in South Korea, an empirical content research was conducted. Even though South Korea's leader was at risk of losing public support to the point where impeachment was mentioned as a possible option, he dramatically reversed public mood to win general elections by a wide margin in April 2020, while the pandemic scenario persisted. To win reelection, democratic administrations are under more pressure to effectively perform crisis management when faced with a crisis. As a result, they are under even more pressure to immediately mobilize public and private resources. The emergency use authorization (EUA) protocol for test kits is an example of "leapfrogging actors" – up-and-coming innovators – who helped turn a pandemic tragedy into a possibility for sustained leadership and for them. The results based on infected premises culling rate ratio is 82.3%, number of measles cases report is 86.4%, spread and epidemic ratio is 84.2%, important of epidemiology is 89.35%, transmission potential of COVID-19 is 91.24% and illustration of epidemic control is 92.45. The results based on infected premises culling rate ratio is 82.3%, number of measles cases report is 86.4%, spread and epidemic ratio is 84.2%, important of epidemiology is 89.35%, transmission potential of COVID-19 is 91.24% and illustration of epidemic control is 92.45.

Spousal Relationship, Gender and COVID -19 Outbreak in South Korea

Spousal Relationship, Gender and COVID -19 Outbreak in South Korea

Learning from Patient 31 case: a cross-cultural perspective of corporate networks’ diffusion ability in Latin America

Objective: This paper has the purpose to discuss how corporate networks’ big linkers constitute a development opportunity area in Latin America. Method: We employ a qualitative analysis that blends social networks literature and builds on interlocking directorates (IntDs) theory with a fascinating case study labeled the ‘Patient 31’ phenomenon that occurred during the coronavirus outbreak in South Korea. Main results: We generate managerial and conceptual insights on the diffusion processes of business practices, which have a series of profound implications for theory and practice on how corporate networks present differences in their diffusion ability. Relevance/Originality: Viral contagion processes are not a secret for health sciences, but they are still underresearched in the context of managerial practices regarding diffusion processes. The COVID-19 virus has been (and is) a significant threat for global health since the beginning of 2020, as well as an operational challenge for almost every organization around the world. Theoretical/Methodological contributions: The results highlight the superspreaders’ high diffusion power, warn about the risks of including ‘Patient 31’- type of spreaders as members of the firms’ boards, and also provide recommendations on how policy makers could harness this diffusion ability over the organizational networks.