Smallpox, caused by the variola virus, remains a potential biosecurity threat despite its eradication. This study develops a mathematical model to evaluate outbreak scenarios and the effectiveness of reactive intervention strategies in controlling transmission, with application to the Republic of Korea. The model incorporates age-stratified contact patterns, contact tracing, and vaccination strategies, including targeted vaccination and mass vaccination. Our simulations demonstrate that early outbreak recognition and rapid intervention are critical in mitigating smallpox spread. In scenarios where vaccination rollout was slow or outbreak recognition was delayed, severe patient numbers exceeded healthcare capacity, highlighting the need for preemptive preparedness. Sensitivity analyses revealed that outbreak recognition timing and contact tracing effectiveness were the most influential factors in determining outbreak severity, with later recognition leading to up to 3.5 times more cumulative cases. Furthermore, we compared different vaccination prioritization strategies and found that prioritizing high-transmission age groups was more effective in reducing total mortality than prioritizing high-risk groups based solely on disease severity. This contrasts with COVID-19 vaccination strategies, which focused on protecting vulnerable populations. These findings underscore the importance of early detection, strategic vaccination, and non-pharmaceutical interventions in mitigating a potential smallpox outbreak. Our model provides a quantitative framework for policymakers to evaluate intervention effectiveness and optimize outbreak response strategies.

BACKGROUND/AIMS:Infection remains the second leading cause of mortality in patients with end-stage renal disease (ESRD). Despite the direct relationship between hemodialysis vascular access-related infections (HD-VARI) and both prognosis and mortality in ESRD patients, there is a paucity of research in this area. METHODS:This retrospective study was performed at a tertiary care hospital in Seoul, Korea, from 2009 to 2020. Medical records of adult patients diagnosed with HD-VARI were assessed. We analyzed the distribution of microorganisms, clinical characteristics according to vascular access type, and evaluated risk factors for treatment failure. RESULTS:Data from a total of 367 patients were included over the 12-year study period. Based on vascular access type, 293 (79.8%) had arteriovenous graft infections, 29 (7.9%) had arteriovenous fistula infections, and 45 (12.3%) had tunneled cuffed catheter infections. Thirty-one (8.4%) patients experienced treatment failure within 90 days. Multivariate analysis identified male sex (odds ratio [OR], 2.343; 95% confidence interval [CI], 1.041-5.274) and metastatic infection (OR, 4.297; 95% CI, 1.516-12.178) as independent predictors of 90-day infection-related treatment failure. Subtotal or total excision (removal) of the infected vascular access significantly decreased the risk of 90-day infection-related treatment failure (OR, 0.337; 95% CI, 0.129-0.876). CONCLUSION:Removal of infected vascular access played a crucial role in reducing infection-related deaths or relapses within 90 days. Management of vascular access infection should be individualized based on patient-specific factors.

Antimicrobial stewardship programs (ASPs) are essential to reduce antimicrobial resistance, but small hospitals often face challenges in securing ASP expertise. A collaborative network model may help overcome this limitation. We analyzed the impact of changes in ASP expertise and implementation on antimicrobial utilization (AU) trends in small community hospitals (less than 100 beds) supported by the Duke Antimicrobial Stewardship Outreach Network (DASON). We assessed the status of ASP expertise and implementation in hospitals with fewer than 100 beds who are members of the 48 hospital DASON network based on the 2021 and 2023 National Healthcare Safety Network (NHSN) annual surveys. AU data were obtained from the DASON database. Hospital were clustered into six groups in 2021 based on the composition of ASP expertise and implementation. Using the same clustering algorithm, hospitals were re-clustered in 2023. Within-hospital differences in implementation and expertise were categorized into worsened, no-change, and improved groups based on changes in their cluster assignments. A mixed-effects model was used to compare AU trends between groups, followed by post hoc analysis of slope changes from 2021 to 2023. Of the 15 DASON member hospitals with fewer than 100 beds, 7 had complete AU and implementation and expertise data for analysis. Two had an infectious diseases (ID) physician, one had an ID pharmacist and six received ID tele-services in 2021. Regarding ASP expertise changes, three , two , and two hospitals were categorized into worsened, no-change, and improved groups, respectively. For ASP implementation, four, one and two hospitals were categorized into worsened, no-change, and improved groups. Linezolid and carbapenem use significantly decreased in the improved expertise group compared to the worsened and no-change groups. In the improved implementation group, AU for hospital-onset infections and Gram-positive organisms decreased significantly. Additionally, use of antifungal agents, carbapenems, linezolid, and vancomycin significantly decreased. Strengthening ASP implementation through a collaborative, consultative model may improve antimicrobial use even in small hospitals where securing expertise is challenging. Elizabeth Dodds Ashley, PharmD, MHS, HealthtrackRx: Advisor/Consultant|UpToDate, Inc.: Author Royalties Melissa D. Johnson, PharmD MHS AAHIVP, Biomeme: Licensed technology, method to detect fungal infection|Biomeme: Licensed technology, method to detect fungal infection|Scynexis: Grant/Research Support|Scynexis: Grant/Research Support|UpToDate: Author Royalties|UpToDate: Author Royalties

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in millions of deaths worldwide and has now become a major respiratory infectious disease. Beyond the direct effects of the viral infection, one of the most significant and concerning issues to emerge is the exacerbated threat of antimicrobial resistance (AMR) by the indirect impacts of COVID-19. Early in the pandemic, widespread empirical antibiotic prescribing occurred despite low bacterial co-infection rates. In addition, azithromycin, whose antiviral effect remains unproven, was frequently used. This high, often unnecessary consumption, coupled with disrupted antimicrobial stewardship (AMS) and infection prevention and control (IPC) programs, created conditions favoring the emergence and spread of AMR. In patients with severe COVID-19, multidrug-resistant organisms were frequently implicated in secondary infections, particularly in intensive care units (ICUs). Nevertheless, previous studies analyzing AMR metrics before and during the COVID-19 pandemic have shown inconsistent results. Strategies to mitigate the COVID-19 pandemic, such as enhanced surveillance, social distancing resulting in lower respiratory infections, and strengthened IPC and targeted AMS interventions, could play protective roles to inhibit the development of AMR. Additionally, targeted interventions-such as prospective audit and feedback, biomarker-guided antibiotic discontinuation, diagnostic stewardship using a rapid molecular test to distinguish viral from bacterial infections, embedding AMS decision support into electronic medical records, and tailoring interventions to high-risk settings such as ICUs- demonstrated the feasibility of reducing unnecessary antimicrobial use (AMU) even during crisis conditions. Also, vaccination against SARS-CoV-2 may indirectly reduce AMU and AMR by lowering the incidence of severe disease and secondary bacterial infections. Future COVID-19-specific AMS frameworks must integrate these experiences during the pandemic. This review synthesizes current evidence on the interplay between COVID-19, AMR, and AMU, and outlines stewardship strategies to reduce AMR in COVID-19 management.

Long coronavirus disease (COVID) is a condition in which coronavirus disease 2019 (COVID-19) symptoms persist for over 3 months, and currently poses a global public health challenge. Due to varying manifestations and lack of standardized definitions, diagnostic methods, and treatments, comprehensive clinical guidelines are required. This review article, summarizing research and expert consensus up to June 2023, provides recommendations for diagnosis and long-term management of long COVID symptoms. It emphasizes thorough patient evaluation, including medical history, physical examinations, and tests, and advocates vaccination and antiviral treatments to reduce risk. Guidelines for long COVID will be updated as new knowledge emerges.

BACKGROUND:This study aimed to analyze the coronavirus disease-19 (COVID-19) response in long-term care hospitals (LTCHs) and establish a preparedness and management framework for addressing novel infectious diseases. METHODS:A national survey was conducted in Korea between June 19 and June 30, 2023. Using an anonymous online questionnaire, the survey gathered information on the general characteristics of participating hospitals, preparedness for infectious diseases in LTCHs prior to the COVID-19 pandemic, preparedness for in-house outbreaks during the COVID-19 pandemic, experiences of in-house COVID-19 outbreaks, and a section related to vaccines and treatments. RESULTS:Of the 1,425 domestic LTCHs, 201 (14.1%) completed the survey. Of the 201, before the COVID-19 pandemic, 24.9% of LTCHs had a disaster preparedness team and 27.9% had conducted training for infectious disease disaster preparedness. During the COVID-19 pandemic, 99.0% of the institutions established response teams for preparedness against COVID-19, and 89.1% of the 201 institutions experienced in-house outbreaks. Most institutions had experienced shortages of materials (78.8%), staff (96.1%), and caregivers (88.3%). The COVID-19 treatments prescribed at the LTCFs were: nirmatrelvir/ritonavir (86.6%), molnupiravir (36.8%), and remdesivir (22.4%). Independent vaccination was administered in 99% of the institutions. CONCLUSIONS:Despite the establishment of response systems, most LTCHs experienced in-house outbreaks during the COVID-19 pandemic. These institutions commonly faced challenges such as staffing shortages and supply constraints. To ensure better preparedness for future outbreaks, infection control systems should be regularly evaluated and maintained through ongoing training, even during non-outbreak periods.

Antimicrobial resistance (AMR) is a global health concern. Antimicrobial stewardship programs (ASPs) are essential for combating AMR. However, the implementation of an ASP in Korea is still in the early stages. Internal medicine (IM) physicians are crucial as both prescribers and ASP leaders within healthcare institutions given the lack of infectious disease (ID) physicians. This review explores the key roles of IM physicians in ASPs, drawing from various successful international cases in which IM physicians engaged in ASPs with and without ID physician involvement. Targeted and detailed education is vital to widen the roles of IM physicians in ASPs and foster appropriate antibiotic prescribing behaviors. Furthermore, ID-physician-guided networks can facilitate the nationwide expansion of ASPs. Finally, reforming the reimbursement system and introducing incentives are necessary to promote ASP adoption and sustainability in Korea.

Given the global threat of antimicrobial-resistant organisms, an effective antimicrobial stewardship program (ASP) is essential. Infectious disease (ID) physicians and ID-trained pharmacists are prioritized as critical core members of ASP in hospital settings, but securing these ID-trained professionals in all settings is challenging. Alternative champions and personnel for implementation may be needed. This narrative review highlights the efficacy of ASP when non-ID-trained physicians and pharmacists are engaged in ASP, showcasing various studies demonstrating significant improvements in antimicrobial utilization, cost, and patient outcomes. Additionally, it discusses the impact of network-based models, such as the Duke Antimicrobial Stewardship Outreach Network, which provides structured support and resources to lower-resourced hospitals to ensure the successful implementation of ASP. Ultimately, this narrative review provides insights into how to structure accountability and pharmacy/stewardship expertise in establishing and expanding ASP nationwide in Korea, where ASP is still in its early stages. In addressing this issue, government initiatives to actively support this effort are essential, and striving to develop evidence-based policies is necessary.

The guidelines presented herewith are based on the "Clinical Practice Guideline Recommendations for Post-Acute Sequelae of COVID-19 (PASC)" published in Infection & Chemotherapy in March 2024; these guidelines have been refined by incorporating the most recent Korean and international research findings and clinical evidence published since then. In the context of patients experiencing various physical and mental symptoms that persist long after the acute phase of coronavirus disease 2019 (COVID-19) infection, the diagnosis and management of PASC has emerged as a novel public health challenge. These guidelines are intended to provide standardized diagnostic and management recommendations applicable to the Korean healthcare setting and were developed through a comprehensive review of existing guidelines from organizations such as the World Health Organization, the United States National Institutes of Health, the United Kingdom National Institute for Health and Care Excellence, and the European Society of Clinical Microbiology and Infectious Diseases, along with the latest meta-analyses and Korean cohort studies. PASC is defined as the persistent presence of symptoms and signs lasting more than 3 months after COVID-19 diagnosis for which the symptoms cannot be explained by alternative diagnoses. The revised guidelines emphasize the importance of integrated management for patients with PASC, including a multidisciplinary approach considering risk groups, symptom-specific assessment, and rehabilitation and psychological interventions, based on a total of 32 key questions. This revision reflects rapidly evolving research trends regarding the long-term effects of COVID-19 and is expected to serve as an evidence-based standard guideline for future patient care, clinical research, and health policy development in Korea.

Owing to concern that carbapenemase-producing strains among carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates is on the rise, we investigated the genetic epidemiology and antimicrobial susceptibilities of clinical CRPA isolates collected in four academic hospitals in Korea. Carbapenemase genes were detected in 46 of 63 CRPA isolates (73.0%) collected between 2021 and 2024, and blaNDM ST773 was the most common genotype (27 isolates, 42.9%), followed by blaNDM ST644 (9 isolates, 14.3%) and blaIMP ST235 (7 isolates, 11.1%). Overall susceptibility to ceftazidime/avibactam was only 17.5%, and none of the carbapenemase-producing isolates were susceptible to it. All ST644 strains were also resistant to aztreonam.

OBJECTIVES: Long-term care facilities (LTCFs) are communal environments for patients with chronic diseases or older adults, making them particularly susceptible to significant harm during infectious disease outbreaks. Nonetheless, LTCFs have historically been subject to less stringent infection prevention and control (IPC) mandates. This study aimed to assess the current state of LTCFs and to develop an IPC system tailored for these facilities following the coronavirus disease 2019 (COVID-19) pandemic.METHODS: We conducted an online survey of 11,366 LTCFs in Korea from December 30, 2022 to January 20, 2023, to evaluate the components of IPC in LTCFs. The infectious diseases targeted for IPC included COVID-19, influenza, and scabies. Additionally, we compared institution-based and home-based long-term care insurance facilities.RESULTS: Overall, 3,537 (31.1%) LTCFs responded to the survey, comprising 1,819 (51.4%) institution-based and 1,718 (48.6%) home-based facilities. A majority (87.4%, 2,376/2,720) of these facilities experienced COVID-19 outbreaks. However, only 42.2% of home-based facilities, in contrast to 90.6% of institution-based facilities, were equipped to manage concurrent COVID-19 cases. Similarly, while 92.1% of institution-based facilities were capable of managing influenza, only 50.5% of home-based facilities could do the same. The incidence of scabies was significantly higher in institution-based facilities than in home-based ones (26.1 vs. 4.3%). Additionally, 88.7% of institution-based facilities managed scabies cases effectively, compared to only 42.1% of home-based facilities.CONCLUSIONS: Approximately half of the LTCFs had a basic capacity to respond to infectious diseases. However, there were differences in response capabilities between institution-based facilities and home-based facilities.

BACKGROUND:Since the emergence of hypervirulent strains of Clostridioides difficile, the incidence of C. difficile infections (CDI) has increased significantly.METHODS:To assess the incidence of CDI in Korea, we conducted a prospective multicentre observational study from October 2020 to October 2021. Additionally, we calculated the incidence of CDI from mass data obtained from the Health Insurance Review and Assessment Service (HIRA) from 2008 to 2020.RESULTS:In the prospective study with active surveillance, 30,212 patients had diarrhoea and 907 patients were diagnosed with CDI over 1,288,571 patient-days and 193,264 admissions in 18 participating hospitals during 3 months of study period; the CDI per 10,000 patient-days was 7.04 and the CDI per 1,000 admission was 4.69. The incidence of CDI was higher in general hospitals than in tertiary hospitals: 6.38 per 10,000 patient-days (range: 3.25-12.05) and 4.18 per 1,000 admissions (range: 1.92-8.59) in 11 tertiary hospitals, vs. 9.45 per 10,000 patient-days (range: 5.68-13.90) and 6.73 per 1,000 admissions (range: 3.18-15.85) in seven general hospitals. With regard to HIRA data, the incidence of CDI in all hospitals has been increasing over the 13-year-period: from 0.3 to 1.8 per 10,000 patient-days, 0.3 to 1.6 per 1,000 admissions, and 6.9 to 56.9 per 100,000 population, respectively.CONCLUSION:The incidence of CDI in Korea has been gradually increasing, and its recent value is as high as that in the United State and Europe. CDI is underestimated, particularly in general hospitals in Korea.

Background: Carbapenem-resistant Enterobacterales (CRE) are an urgent threat to healthcare, but the epidemiology of these antimicrobial-resistant organisms may be evolving in some settings since the COVID-19 pandemic. An updated analysis of hospital-acquired CRE (HA-CRE) incidence in community hospitals is needed. Methods: We retrospectively analyzed data on HA-CRE cases and antimicrobial utilization (AU) from two community hospital networks, the Duke Infection Control Outreach Network (DICON) and the Duke Antimicrobial Stewardship Outreach Network (DASON) from January 2013 to June 2023. The zero-inflated negative binomial regression model was used owing to excess zeros. Results: 126 HA-CRE cases from 36 hospitals were included in the longitudinal analysis. The pooled incidence of HA CRE was 0.69 per 100,000 patient days (95% confidence interval [95% CI], 0.57-0.82 HA-CRE rate significantly decreased over time before COVID-19 (rate ratio [RR], 0.94 [95% CI, 0.89-0.99]; p = 0.02), but there was a significant slope change indicating a trend increase in HA-CRE after COVID-19 (RR, 1.32 [95% CI, 1.06-1.66]; p = 0.01). In 21 hospitals participating in both DICON and DASON from January 2018 to June 2023, there was a correlation between HA-CRE rates and AU for CRE treatment (Spearman's coefficient = 0.176; p < 0.01). Anti-CRE AU did not change over time, and there was no level or slope change after COVID. Conclusions: The incidence of HA-CRE decreased before COVID-19 in a network of community hospitals in the southeastern United States, but this trend was disrupted by the COVID-19 pandemic.

Smallpox, caused by the variola virus, is one of the most devastating diseases in human history and was eradicated through global vaccination efforts by 1980. Despite its eradication, the virus remains in high-security laboratories for research purposes, posing the potential risk of bioterrorism. This study developed a mathematical model to analyze potential smallpox epidemics by incorporating factors such as age groups, heterogeneous contact patterns, and various intervention strategies including contact tracing, ring vaccination, and mass vaccination. The model simulations indicated that the Republic of Korea’s current plans for negative-pressure isolation beds should suffice under most scenarios, but extreme worst-case scenarios could overwhelm healthcare capacity. This study highlights the critical importance of non-pharmaceutical interventions and strategic vaccination prioritization for controlling outbreaks. These findings provide valuable guidance for public health officials and policymakers in preparing for potential bioterrorism threats and emerging infectious diseases. Furthermore, emphasizes the need for comprehensive preparedness and robust response strategies. The proposed framework applies to smallpox and to other infectious diseases, offering insights for future outbreak management. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Yes ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study is a simulation-based research, with no human subjects involved therefore, IRB approval is not required. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All relevant data are within the manuscript.

BACKGROUND:The incidence of healthcare-associated infections, particularly injection-related infections, can increase patient comorbidities even in countries with adequate medical resources. Although there are clear guidelines for injection practices to prevent infections, their application in clinical settings is insufficient. Therefore, the objective of this study was to identify factors affecting injection practices associated with reduced infections by conducting surveys targeting practicing healthcare providers involved in administering injections at each healthcare organization and performing data analysis. METHODS:We administered a survey to healthcare providers responsible for injection practices at each healthcare organization that included items related to infection-safe injection practice guidelines. All survey questions were reviewed by an expert panel of infectious disease and infection control nurses. Survey contents were subjected to exploratory factor analysis (EFA), confirmatory factor analysis, and multivariable robust regression tests to determine the impact of each factor and their correlations. RESULTS:A total of 842 questionnaires were analyzed. Each questionnaire was classified into four factors: reuse and contamination, compliance with aseptic technique, exchange of infusion set, and use of multidose vials. Nurses with higher careers showed more compliance. Education within one year and awareness of each item of the questionnaire had positive associations with proper injection practice. CONCLUSIONS:Education is thought to be the most important factor in good injection practices that could reduce infections. Relevant knowledge through timely training is expected to have a positive impact on performance and compliance related to safe injections.

"Long COVID" is a term used to describe a condition when the symptoms and signs associated with coronavirus disease 2019 (COVID-19) persist for more than three months among patients infected with COVID-19; this condition has been reported globally and poses a serious public health issue. Long COVID can manifest in various forms, highlighting the need for appropriate evaluation and management by experts from various fields. However, due to the lack of clear clinical definitions, knowledge of pathophysiology, diagnostic methods, and treatment protocols, it is necessary to develop the best standard clinical guidelines based on the scientific evidence reported to date. We developed this clinical guideline for diagnosing and treating long COVID by analyzing the latest research data collected from the start of the COVID-19 pandemic until June 2023, along with the consensus of expert opinions. This guideline provides recommendations for diagnosis and treatment that can be applied in clinical practice, based on a total of 32 key questions related to patients with long COVID. The evaluation of patients with long COVID should be comprehensive, including medical history, physical examination, blood tests, imaging studies, and functional tests. To reduce the risk of developing long COVID, vaccination and antiviral treatment during the acute phase are recommended. This guideline will be revised when there is a reasonable need for updates based on the availability of new knowledge on the diagnosis and treatment of long COVID.

Objective: We investigated gender differences in psychosocial determinants that affect hand hygiene (HH) performance among physicians. Design: The survey included a structured questionnaire with 7 parts: self-assessment of HH execution rate; knowledge, attitude, and behavior regarding HH; internal and emotional motivation for better HH; barriers to HH; need for external reminders; preference for alcohol gel; and embarrassment due to supervision. Setting: The study was conducted across 4 academic referral hospitals in Korea. Participants: Physicians who worked at these hospitals were surveyed. Methods: The survey questionnaire was sent to 994 physicians of the hospitals in July 2018 via email or paper. Differences in psychosocial determinants of HH among physicians were analyzed by gender using an independent t test or the Fisher exact test. Results: Of the 994 physicians, 201 (20.2%) responded to the survey. Among them, 129 (63.5%) were men. Male physicians identified 4 barriers as significant: time wasted on HH ( P = .034); HH is not a habit ( P = .004); often forgetting about HH situations ( P = .002); and no disadvantage when I do not perform HH ( P = .005). Female physicians identified pain and dryness of the hands as a significant obstacle ( P = .010), and they had a higher tendency to feel uncomfortable when a fellow employee performed inadequate HH ( P = .098). Among the respondents, 26.6% identified diversifying the types of hand sanitizers as their first choice for overcoming barriers to improving HH, followed by providing reminders (15.6%) and soap and paper towels in each hospital room (13.0%). Conclusion: A significant difference in the barriers to HH existed between male and female physicians. Promoting HH activities could help increase HH compliance.

Abstract Background Clostridioides difficile infection (CDI) is a representative healthcare-associated infection, and the incidence rate continues to increase in Korea. The purpose of this study is to identify antibiotics that are highly related to CDI incidence in Korean hospitals. Methods From January-December 2019, all antibiotic prescription records, CDI test results, and a daily number of hospitalized patients were retrospectively collected from 10 university-affiliated hospitals in Korea. To exclude duplication, CDI tests that were conducted within 10 days after conducting previous CDI tests were excluded. When a positive result was detected from C. difficile toxin assay or PCR tests, we considered it as CDI. Antibiotics were defined as drugs corresponding to J01 in the WHO ATC classification, excluding anti-tuberculosis drugs, anti-parasitic drugs, antiviral drugs, and local antibiotics. The antibiotic usage was calculated as Days of Therapy (DOT). The CDI incidence rate and antibiotic usage were collected on a weekly basis and then corrected to 1,000 patient days. The correlation between CDI incidence rate and antibiotic usage was analyzed using the cross-correlation function test. Results CDI incidence and total antibiotic usage in each hospital ranged from 0.49-1.58/1,000 patient-days and 588.7-1000.4 DOT/1,000 patient-days, respectively. Cross-correlation function test shows that antibiotics that are highly related to CDI incidence were 2nd generation cephalosporin that was prescribed 6 weeks prior to CDI event (coefficient 0.320, P = 0.021), 4th generation cephalosporin that was prescribed 1 week prior to CDI event (coefficient 0.307, P = 0.027), and beta-lactam/beta-lactamase inhibitors (with anti-pseudomonal effects) that was prescribed 1 week prior to CDI event (coefficient 0.272, P = 0.050), lincosamide that was prescribed 2 weeks prior to CDI event (coefficient 0.278, P = 0.045), and oxazolidinone that was prescribed 8 weeks prior to CDI event (coefficient 0.362, P = 0.008). Cross-correlation coefficients between Clostridioides difficile infection incidence and antibiotic usage Conclusion Antibiotics highly associated with CDI incidence in Korean hospitals were second-generation cephalosporin, fourth-generation cephalosporin, beta-lactam/beta-lactamase inhibitors (with anti-pseudomonal effects), lincosamide, and oxazolidinone. Disclosures All Authors: No reported disclosures