Objectives: In May 2025, clusters of salmonellosis were identified in 7 cities in the Republic of Korea, all associated with consumption of identical bakery products. This investigation aimed to characterize the outbreak, identify potential contributing factors, and inform strategies for preventing similar multi-facility foodborne outbreaks. Methods: A case series study was conducted among individuals who consumed Manufacturer H’s Product I and Product II on May 15–16, 2025 at 7 facilities (n = 1,235). Clinical specimens from symptomatic individuals, retained food samples, and environmental samples were collected and tested. Food-exposure histories were assessed, and active case finding was implemented across all supplied facilities. Traceback investigations were conducted at the manufacturer, distributor, and egg farms. Human and food isolates underwent pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS). Results: A total of 323 cases met the outbreak case definition (attack rate, 26.2%), of which 48 were laboratory-confirmed. Salmonella Enteritidis was isolated from both clinical specimens and retained bakery products. PFGE patterns were indistinguishable between human and food isolates, and WGS demonstrated high genetic relatedness. These findings confirmed a common-source outbreak linked to the implicated bakery products. Conclusion This outbreak underscores the value of integrating epidemiological investigation, active case finding, and molecular typing to identify common food vehicles in outbreaks involving widely distributed manufactured foods. Coordinated collaboration between public health and food safety authorities is essential for the effective detection, response, and prevention of multi-facility foodborne outbreaks.

Although venous invasion (VI) is associated with distant metastasis and observed in >50% of pT2–4 colorectal cancers (CRCs), the role of VI in pT1 CRCs is not well-defined. Methods: Thirty-four surgically resected pT1 CRCs were reevaluated for 2-dimensional (2D) VI using hematoxylin and eosin (H&E)–stained slides with additional elastic and desmin immunohistochemical staining (cohort A). Additionally, 27 pT1 CRCs without knowing VI status were selected for 3-dimensional (3D) VI evaluation only (cohort B). All 61 cases (cohorts A and B) were studied in 3D using tissue clearing. Results: VI was detected more commonly in 3D (17/34, 50.0%) than in 2D H&E slide evaluation (9/34, 26.5%, p = .047). When VI was identified in 3D (27/61, 44.3%), the most common phase was that of intraluminal growth (22/27, 81.5%), followed by intravasation (7/27, 25.9%) and extravasation (5/27, 18.5%). E-cadherin expression was characterized in 3D in foci of VI and varied in each phase of invasion. Conclusions: All three phases were observed in VI of pT1 CRCs. The extravasation of neoplastic cells from foci of VI in pT1 CRC suggests that VI could be a route of intratumoral spreading in a subset of pT1 CRCs.

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.

Background and Objectives: Accumulating evidence shows that sodium-glucose cotransporter 2 inhibitors (SGLT2is) reduce adverse cardiovascular outcomes. However, whether SGLT2i, compared with other antidiabetic drugs, reduce the new development of atrial fibrillation (AF) is unclear. In this study, we compared SGLT2i with dipeptidyl peptidase-4 inhibitors (DPP-4is) in terms of reduction in the risk of AF in individuals with type 2 diabetes. Methods: We included 42,786 propensity score-matched pairs of SGLT2i and DPP-4i users without previous AF diagnosis using the Korean National Health Insurance Service database between May 1, 2016, and December 31, 2018. Results: During a median follow-up of 1.3 years, SGLT2i users had a lower incidence of AF than DPP-4i users (1.95 vs. 2.65 per 1,000 person-years; hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.55–0.97; p=0.028]). In individuals without heart failure, SGLT2i users was associated with a decreased risk of AF incidence (HR, 0.70; 95% CI, 0.52–0.94; p=0.019) compared to DPP-4i users. However, individuals with heart failure, SGLT2i users was not significantly associated with a change in risk (HR, 1.04; 95% CI, 0.44–2.44; p=0.936). Conclusions In this nationwide cohort study of individuals with type 2 diabetes, treatment with SGLT2i was associated with a lower risk of AF compared with treatment with DPP-4i.

Purpose: Since accurate lung cancer segmentation is required to determine the functional volume of a tumor in [ 18 F]FDG PET/CT, we propose a two-stage U-Net architecture to enhance the performance of lung cancer segmentation using [ 18 F]FDG PET/CT. Methods: The whole-body [ 18 F]FDG PET/CT scan data of 887 patients with lung cancer were retrospectively used for network training and evaluation. The ground-truth tumor volume of interest was drawn using the LifeX software. The dataset was randomly partitioned into training, validation, and test sets. Among the 887 PET/CT and VOI datasets, 730 were used to train the proposed models, 81 were used as the validation set, and the remaining 76 were used to evaluate the model. In Stage 1, the global U-net receives 3D PET/CT volume as input and extracts the preliminary tumor area, generating a 3D binary volume as output. In Stage 2, the regional U-net receives eight consecutive PET/CT slices around the slice selected by the Global U-net in Stage 1 and generates a 2D binary image as the output. Results: The proposed two-stage U-Net architecture outperformed the conventional one-stage 3D U-Net in primary lung cancer segmentation. The two-stage U-Net model successfully predicted the detailed margin of the tumors, which was determined by manually drawing spherical VOIs and applying an adaptive threshold. Quantitative analysis using the Dice similarity coefficient confirmed the advantages of the two-stage U-Net. Conclusion The proposed method will be useful for reducing the time and effort required for accurate lung cancer segmentation in [ 18 F]FDG PET/CT.

Mitral regurgitation (MR) is the most common heart disease in small-breed dogs. Mitral repair, which comprise artificial chorda tendineae implantation and mitral annuloplasty, has become the mainstay of treatment in the veterinary field. We report on two small dogs who underwent mitral repair surgery for MR. A Hegar dilator was used during mitral annuloplasty for accurate and reproducible surgery. In both cases, mitral regurgitant flow almost disappeared after surgery, and clinical signs improved. The treatment regimen was terminated 3 months after the surgery. We concluded that using a Hegar dilator may facilitate mitral valve repair surgery.

Purpose: Ankle sprains are among the most common musculoskeletal injuries, and many videos have been shared with patients through YouTube. YouTube allows the easy sharing of information, but there are accuracy and reliability issues due to the lack of verification processes for video producers. This study evaluated ankle sprain videos on YouTube and the correlation between the video scores and viewer preferences using “the number of likes and views”. Materials and Methods: For analysis, the words “ankle sprains”, “ankle exercise”, and “ankle rehabilitation” were searched on YouTube. Only videos taken in Korean were analyzed, and videos with less than 10,000 views and for commercial purposes were excluded. For 31 videos, two orthopedic surgeons and one orthopedic resident used one evaluation tool to evaluate the video quality with up to 30 points for subcategories. The scores between each evaluator were then averaged to evaluate the video quality. To reflect the viewer preferences, “the number of likes and views” were analyzed, and the relationship between the video score and “the number of likes and views” of the video was analyzed statistically. Results: The average score for the video was 9.33. The average scores for subcategories were anatomy and symptoms, 0.90; biomechanics and trauma-mechanism, 0.61; imaging quality, 0.95; clinical evaluation and physical examination, 0.61; treatment, 1.41; rehabilitation, 2.39; prevention and after effects, 0.89; and overall video quality, 1.61. The average of “the number of views” was 50,218.35 times, and “the number of likes” was 893.77 times. No correlation was observed between the video scores and “the number of likes and views”. Conclusion Most videos posted on YouTube did not provide high-quality medical information on ankle sprain, and there was no correlation between the video scores and viewer preferences. This suggests that incorrect medical information is being transmitted to patients, which can be harmful. Therefore, it is necessary to present the latest trend treatment and rehabilitation protocols for ankle sprains in an expert council and promote it through various channels.

Since a novel beta-coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in December 2019, there has been a rapid global spread of the virus. Genomic surveillance was conducted on samples isolated from infected individuals to monitor the spread of genetic variants of SARS-CoV-2 in Korea. The Korea Disease Control and Prevention Agency performed whole genome sequencing of SARS-CoV-2 in Korea for 1 year (January 2020 to January 2021). A total of 2,488 SARSCoV-2 cases were sequenced (including 648 cases from abroad). Initially, the prevalent clades of SARSCoV-2 were the S and V clades, however, by March 2020, GH clade was the most dominant. Only international travelers were identified as having G or GR clades, and since the first variant 501Y.V1 was identified (from a traveler from the United Kingdom on December 22 nd , 2020), a total of 27 variants of 501Y.V1, 501Y.V2, and 484K.V2 have been classified (as of January 25 th , 2021). The results in this study indicated that quarantining of travelers entering Korea successfully prevented dissemination of the SARS-CoV-2 variants in Korea.

Background: Previous studies suggested the correlation between thyroid and kidney functions, especially the high prevalence of hypothyroidism in chronic kidney disease. This study aimed to evaluate the influence of hypothyroidism on kidney function in Korean adults by using data from a representative nationwide survey. Methods: This was a cross-sectional study composed of 5,250 individuals aged ≥19 years who were enrolled in the sixth Korea National Health and Nutrition Examination Survey. The participants were classified into three groups of patients with euthyroidism, subclinical hypothyroidism, and overt hypothyroidism according to thyroid function. Chronic kidney disease was defined as having a decreased estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2. Univariate and multivariate logistic regression analyses were used to evaluate the prevalence and adjusted odds ratio (aOR) of chronic kidney disease. Results: Compared with the euthyroidism group, the subclinical and overt hypothyroidism groups showed higher prevalence rates of chronic kidney disease in both sexes. This tendency was significant in the elderly people aged ≥65 years. In the multivariate logistic regression analysis, the subclinical hypothyroidism group did not show a significant difference (adjusted odds ratio [aOR], 1.78; 95% confidence interval [CI], 0.82–3.87) from the euthyroidism group. In the overt hypothyroidism group, the aOR of chronic kidney disease was significantly higher (aOR, 5.90; 95% CI, 1.73– 20.15) than that in the euthyroidism group. Conclusion Overt hypothyroidism was associated with decreased eGFR and may be considered as an independent risk factor of chronic kidney disease.

Background: Upper gastrointestinal endoscopy is becoming a common technique used by primary care physicians, so appropriate education using adummy is beneficial for the trainees. However, because dummies are expensive, only a few hospitals have dummies. In this study, we investigatedwhether a simplified upper gastrointestinal endoscopic simulator created using recycled materials can be useful in endoscopic education. Methods: The simplified upper gastrointestinal endoscopic simulator was prepared using materials that were readily available around us. Focus groupinterviews were conducted with five family medicine trainees for 60 minutes using a semi-structured questionnaire. All conversations were recordedand transcribed after they provided informed consent. Data were analyzed using qualitative analysis methods. Results: Family medicine trainees believe that upper gastrointestinal endoscopic training is essential for primary care physicians and can be helpful intheir job after training. However, they were concerned about the possibility of endoscopic complications and difficulty in endoscopy operation. Allof them said that the simplified upper gastrointestinal endoscopic simulator helped reduce their fear and also helped them become familiar withanatomic positions. The simplified upper gastrointestinal endoscopic simulator also aroused their interest and motivated them to learn. Conclusion Overall, the simplified upper gastrointestinal endoscopy simulator seemed helpful for trainees of upper gastrointestinal endoscopy. Theuse of a simplified upper gastrointestinal endoscopy simulator could be considered in training hospitals that do not have enough financial resources.Further quantitative studies are needed to generate further evidence.