Risk factors for carbapenem‐resistant Enterobacterales infection among hospitalized patients with previous colonization

BACKGROUND: We aimed to identify the risk factors for subsequent carbapenem‐resistant Enterobacterales (CRE) infections in patients with initial rectal colonization with CRE. METHODS: We conducted a retrospective case–control study on inpatients with rectal CRE colonization between January 2019 and December 2020. Clinical and microbiological data were extracted from hospital patients' medical records and the clinical microbiology laboratory. Risk factors were assessed and compared between patients with CRE colonization who had subsequent infections and those who did not have infections. RESULTS: Among 1064 patients screened for CRE, we enrolled 205 patients with rectal CRE colonization. Among the 205 colonized bacteria, 78.5% were Klebsiella pneumoniae, with 62.9% of them producing Klebsiella pneumoniae carbapenemase (KPC). Multivariate logistic regression analysis revealed that more than three times hospitalization (p = 0.026), being in a coma (p = 0.019), and exposure to carbapenems (p = 0.015) were independent risk factors for CRE clinical infection among CRE rectal carriers. CONCLUSION: This is the first study to report that more than three times hospitalization is an independent risk factor for subsequent CRE clinical infection in CRE intestinal carriers. Carbapenem‐resistant Klebsiella pneumoniae is the most important species isolated from hospitalized CRE rectal carriers and is the most common cause of subsequent infections.