Background: Since 2003, the H5 highly pathogenic avian influenza (HPAI) subtype has caused massive economic losses in the poultry industry in South Korea. The role of inland water bodies in avian influenza (AI) outbreaks has not been investigated. Identifying water bodies that facilitate risk pathways leading to the incursion of the HPAI virus (HPAIV) into poultry farms is essential for implementing specific precautionary measures to prevent viral transmission. Objectives: This matched case-control study (1:4) examined whether inland waters were associated with a higher risk of AI outbreaks in the neighboring poultry farms. Methods: Rivers, irrigation canals, lakes, and ponds were considered inland water bodies.The cases and controls were chosen based on the matching criteria. The nearest possible farms located within a radius of 3 km of the case farms were chosen as the control farms.The poultry farms were selected randomly, and two HPAI epidemics (H5N8 [2014–2016] and H5N6 [2016–2017]) were studied. Conditional logistic regression analysis was applied. Results: Statistical analysis revealed that inland waters near poultry farms were significant risk factors for AI outbreaks. The study speculated that freely wandering wild waterfowl and small animals contaminate areas surrounding poultry farms. Conclusions Pet birds and animals raised alongside poultry birds on farm premises may wander easily to nearby waters, potentially increasing the risk of AI infection in poultry farms. Mechanical transmission of the AI virus occurs when poultry farm workers or visitors come into contact with infected water bodies or their surroundings. To prevent AI outbreaks in the future, poultry farms should adopt strict precautions to avoid contact with nearby water bodies and their surroundings.

BACKGROUND: About more than 70% of Staphylococcus aureus isolates in tertiary-care hospitals are known to be resistant to methicillin in Korea. But the prevalence of methicillin-resistant S. aureus (MRSA) in the community and non-tertiary hospitals has not been known yet. The aim of this study was to determine the prevalence of resistance among S. aureus isolates in non-tertiary hospitals. METHODS: The isolates were collected at one laboratory center from August 1998 to May 1999. Antimicrobial susceptibility tests against 11 antibiotics were performed by disk diffusion method. Minimum inhibitory concentrations (MIC) for oxacillin and vancomycin were determined by microbroth dilution method. The mecA gene was detected by polymerase chain reaction. The medical facilities which sent specimen to the laboratory were classified into 3 groups; clinic, hospital and general hospital. RESULTS: Of total 469 S. aureus isolates, 296 (63.1%) were from pus, 47 (10.0%) from sputum, 23 (5.0%) from urine, and 22 (4.6%) from blood. Overall prevalence of MRSA in non-tertiary hospital was 43.5% (204/469). Among 3 hospital groups, MRSA in general hospitals (55%) was significantly more prevalent than in hospitals (40%) or clinics (37%). MICs of oxacillin against MRSA isolated from pus and blood ranged from 8 to > or =256 microgram/mL, but 74% (83 isolates) of them was > or =256 microgram/mL. MICs of vancomycin were distributed from 1 to 2 microgram/mL, irrespective of methicillin resistance or hospital groups. The mecA gene was detected in all of methicillin-resistant isolates with MICs of < or =128 microgram/mL. CONCLUSION: In non-tertiary hospitals, 43% of S. aureus isolates were methicillin resistant. This result showed that MRSA in non-tertary hospitals was less prevalent than in tertiary hospitals.
Anti-Bacterial Agents ; Diffusion ; Drug Resistance, Microbial* ; Hospitals, General ; Humans ; Korea ; Methicillin ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Microbial Sensitivity Tests ; Oxacillin ; Polymerase Chain Reaction ; Prevalence ; Sputum ; Staphylococcus aureus* ; Staphylococcus* ; Suppuration ; Tertiary Care Centers ; Vancomycin

Objectives: In March 2023, an alternative school in the Republic of Korea reported 12 cases of shigellosis. This study aims to analyze the epidemiological characteristics in order to determine the cause of the cluster outbreak of shigellosis and to develop prevention strategies. Methods: This study focused on 12 patients with confirmed Shigella infection and investigated their demographics, clinical features, epidemiology, diagnostics, and antimicrobial susceptibility. Following the identification of Shigella, we conducted follow-up rectal smear cultures to manage patients, implementing isolation and control measures. Results: This study investigated the emergence of multidrug-resistant Shigella following missionary activities in Cambodia, documenting a cluster infection within an alternative school in Daejeon, the Republic of Korea. The outbreak affected 56 participants, resulting in the confirmation of 12 cases. The incidence rates varied by gender and occupation, with higher rates among males and teachers. All 12 cases demonstrated multidrug resistance. Challenges included delayed pathogen confirmation and suboptimal adherence to isolation criteria. The incident prompted revisions in the criteria for isolation release, focusing on symptom resolution. The study underscores the necessity for strengthened surveillance, educational initiatives focusing on prevention in endemic areas, and improved oversight of unlicensed educational establishments. Conclusion Successful response strategies included swift situation assessment, collaborative efforts, effective infection control measures, and modified criteria for isolation release. Continued surveillance of multidrug-resistant strains is recommended, especially in regions with a high prevalence.

OBJECTIVES: Salmonellosis outbreaks occurred at 2 restaurants 2 days apart, and an epidemiological investigation was conducted to determine whether the outbreaks were connected. METHODS: Case studies were conducted for both outbreaks. Stool samples were collected from individuals, and food samples were collected from the restaurants. Pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing analyses were performed on outbreak-related Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) isolates. Traceback investigations were also conducted for the ingredients from gimbap restaurants A and B. RESULTS: In total, 106 people from gimbap restaurant A and 5 from gimbap restaurant B met the case definition. Salmonella Enteritidis was detected in samples from 2 food handlers, 22 patients, and 1 food (iceberg lettuce) at gimbap restaurant A and from 1 patient at gimbap restaurant B. According to PFGE, all isolates were identified as SEGX01.089. The molecular typing of all isolates showed the same pattern, and the genetic distance was close according to phylogenetic analysis. Eggs were the only food ingredient that was supplied to both gimbap restaurants. CONCLUSIONS The outbreaks were caused by Salmonella Enteritidis, and the source of infections was suspected to be contaminated eggs. To prevent foodborne outbreaks of Salmonella, restaurants should heat eggs sufficiently, and egg farms need to establish management systems that prevent Salmonella infections.