Incidence and factors associated with carbapenem-resistant Enterobacterales infection among hospitalized internal medicine patients in Korea: a retrospective observational study.

PURPOSE: This study investigated the incidence, microbiological characteristics, and factors associated with carbapenem-resistant Enterobacterales (CRE) infection among internal medicine patients admitted to general wards at a general hospital. METHODS: This retrospective study was conducted among internal medicine patients admitted to general wards at a general hospital in Korea between January 2023 and December 2024. Among 25,341 admissions, 53 patients with confirmed CRE infection were identified as the case group. A control group comprising 212 patients without CRE infection was selected using simple random sampling at a 4:1 ratio. Multivariable logistic regression analysis was performed to identify factors associated with CRE infection. RESULTS: The incidence of CRE infection was 2.1 per 1,000 admissions and 0.36 per 1,000 patient-days. Klebsiella pneumoniae was the predominant pathogen, and Klebsiella pneumoniae carbapenemase and New Delhi metallo-β-lactamase were the most common carbapenemase genotypes. Multivariable analysis demonstrated that carbapenem use, acid-suppressive therapy, intensive care unit admission within the previous 3 months, bronchoscopy, and higher Charlson Comorbidity Index scores were significantly associated with CRE infection. CONCLUSION: These findings underscore the need for targeted prevention strategies in general wards, particularly for patients with substantial comorbidities and recent healthcare exposures. Implementing robust antimicrobial stewardship programs, strengthening infection control practices for high-risk procedures, and establishing proactive surveillance systems may help reduce the burden of CRE infections in general hospitals.