Hypersensitivity reactions (HSRs) to iodinated contrast media (ICM) can range from mild cutaneous symptoms to life-threatening anaphylaxis. In patients with a history of ICM hypersensitivity, avoidance of the culprit agent is generally recommended. This case report describes a successful desensitization in a 56-year-old man with recurrent HSRs to multiple agents including ioversol, iohexol, iobitridol, and iopamidol. Intradermal testing was performed to identify potentially safe alternatives; however, all tested agents, including iohexol, ioversol, iobitridol, iopamidol, iodixanol, iomeprol, and iopromide, yielded positive results. Given the clinical necessity of transcatheter arterial chemoembolization, a 13-step rapid desensitization protocol with iodixanol was implemented. The procedure was completed without any breakthrough reactions. This case highlights desensitization as a feasible and effective strategy for patients with hypersensitivity to multiple ICM agents.

Objectives: This study investigated a cluster of secondary human-to-human transmission of severe fever with thrombocytopenia syndrome (SFTS) in a hospital setting, focusing on infection risk factors and the role of personal protective equipment (PPE). Methods: A descriptive epidemiological investigation was conducted following the death of anindex patient with laboratory-confirmed SFTS. A total of 27 close contacts, including healthcareworkers and a funeral director, were monitored for symptoms. Suspected cases underwent real-time reverse transcription polymerase chain reaction testing. Clinical features, PPE use, and exposure histories were analyzed. The Fisher exact test was used to assess associations between PPE use and infection. Viral genotyping and sequence analyses were performed to evaluate transmission routes. Results: The index patient deteriorated rapidly and died after repeated cardiopulmonaryresuscitation (CPR), during which 8 secondary cases occurred. Most infections were identifiedamong individuals involved in CPR or postmortem care without adequate PPE. Although notstatistically significant, infection rates were higher among those who did not wear masks or who used low-filtration masks. Proper use of gloves, gowns, and goggles was associated withlower infection rates. Cycle threshold values in secondary cases (range, 34–39) were higherthan in the index case (14.07), suggesting lower viral loads. Sequence analysis demonstrated99.6%–100% homology between the index and secondary cases; all isolates were genotype B, indicating direct transmission. Conclusion This study provides molecular and epidemiological evidence of nosocomial SFTS transmission. Inadequate PPE use during aerosol-generating procedures likely facilitated infection, underscoring the importance of strict adherence to PPE protocols and reinforced infection control practices.

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.

Background: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance. Methods: We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed. Results: Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55. Conclusions Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.

Background: Rapid pathogen identification and antibiotic-susceptibility tests (ASTs) are important for treating bloodstream infections. We compared the performance of the QMAC-dRAST and BD Phoenix M50 direct AST (dPhoenix) systems using bacterial pellets prepared from positive blood culture broth and evaluated their impact on treatment modification. Methods: Direct AST results for 106 Enterobacterales isolates were retrospectively reviewed. Conventional broth microdilution was used to calculate categorical agreement (CA), very major error (VME), major error (ME), and minor error (mE). For isolates showing high VMEs in both methods, supplementary tests were performed. Clinical impact was evaluated by calculating the time required to obtain AST results (time-to-result) and observing changes in antibiotics prescribed after performing ASTs. Results: Both systems showed acceptable overall CA, VME, ME, and mE values (QMACdRAST: 93.6%, 1.6%, 0.9%, and 5.3%, respectively; dPhoenix: 93.1%, 0.9%, 0.6%, and 6.2%, respectively). Piperacillin–tazobactam showed high VMEs with QMAC-dRAST (4/20, 20.0%) and dPhoenix (3/20, 15.0%). Colony AST on 13 isolates revealed that QMACdRAST testing yielded lower minimal inhibitory concentrations (MICs) for piperacillin–tazobactam with three isolates, whereas dPhoenix testing yielded higher MICs with two isolates and lower MICs with two isolates. The average time-to-result was 20.8 hr and 30.1 hr for QMAC-dRAST and dPhoenix, respectively (P < 0.001). After AST, the number of optimal treatments increased from 43 (46.7%) to 72 (78.3%) (P < 0.001). Conclusions The QMAC-dRAST and dPhoenix systems provided reliable AST results with a short time-to-result. However, we recommend performing complementary tests, such as the disk diffusion test, for piperacillin–tazobactam.

Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

The gastrointestinal stromal tumor (GIST) is one of the most common mesenchymal tumors of the gastrointestinal tract. Between the 1990s and early 2000s, GIST was identified as a tumor characterized by KIT or PDGFRA mutations, resulting in imatinib being established as an effective targeted therapy. However, with advances in molecular diagnostics, approximately 10%–15% of GISTs have been reported to harbor alternative mutations, such as those in the succinate dehydrogenase subunit genes and BRAF, leading to the development of additional targeted therapies. GISTs exhibit a wide spectrum of clinical behaviors, ranging from indolent to highly aggressive, prompting the development of diverse risk classification systems. However, multiple systems remain in use, leading to inconsistent pathologic reports. Moreover, the mitotic counting method—a key factor in risk stratification—has become a major source of confusion among pathologists owing to the adoption of digital pathology and discrepancies between updated international guidelines and outdated reimbursement requirements. These inconsistencies have hindered pathologic reporting and communication between pathologists and clinicians. This review comprehensively overviews the historical background, molecular subtypes, and risk classification systems of GIST, focusing on evolving issues in mitotic rate evaluation and the application of risk classification systems in clinical practice.

Purpose: This study examined the levels of end-of-life care preparedness, importance, performance, and educational needs among community-based home care workers and identified factors influencing end-of-life care performance to inform hospice/end-of-life care education programs. Methods: This study used a descriptive, correlational design. The participants were 152 community-based home care workers with at least 6 months of work experience. Data were collected using structured questionnaires that assessed end-of-life care preparedness, importance, performance, and educational needs. Data were analyzed using descriptive statistics, correlation analysis, importance-performance analysis (IPA), and hierarchical multiple regression analysis using SPSS version 29.0. Results: Overall, end-oflife care performance was significantly lower than its perceived importance (t=14.41, P＜ 0.001), with the largest gaps observed in the caregiving support and emotional support domains. In the IPA, multiple items related to death preparation for patients/families, spiritual/ emotional support, and care around the time of death fell into the low-importance/lowperformance quadrant. Educational needs positively correlated with importance, intention,confidence, preparedness, and performance. In hierarchical regression, preparedness (β =0.21, P=0.03) and importance (β=0.26, P＜0.001) significantly predicted performance, explaining 15% of variance. Conclusion End-of-life care performance among home care workers was influenced by psychological factors, including preparedness, importance, and confidence in end-of-life care, as well as institutional and environmental factors. Standardized educational programs and organizational support are required to improve the quality of community-based end-of-life care.

Purpose: This study aimed to identify the factors influencing end-of-life care performance among community-based care workers prior to the implementation of the Integrated Care Support Act in South Korea. Methods: A cross-sectional survey was conducted among 153 community care workers who provided home-based services. Data were collected using structured questionnaires that assessed perceptions of a good death, attitudes toward end-of-life care, end-of-life care stress, and end-of-life care performance. Data analysis included descriptive statistics, independent t tests, Pearson correlation coefficients, and hierarchical multiple regression using SPSS version 29.0. Results: End-of-life care performance demonstrated a significant positive correlation with end-of-life care stress (r=0.43,P＜0.001). Hierarchical regression analysis identified end-of-life care stress (β=0.32, P＜ 0.001), gender (female; β=–0.20, P=0.01), and intention to participate in end-of-life care education (β=–0.20, P=0.01) as significant predictors. The final model explained 25%of the variance in end-of-life care performance. Conclusion End-of-life care stress was the strongest predictor of performance among community-based care workers, along with gender and intention to participate in end-of-life care education. These findings suggest that, when appropriately managed and supported, end-of-life care stress may function as a motivating factor rather than solely a burden. Therefore, structured education and emotional support interventions—such as debriefing and peer-based supervision—are recommended. Additionally, the implementation of the Integrated Care Support Act should be accompanied by institutional systems that facilitate effective end-of-life care practices.