Risk factors for predicting extended-spectrum β-lactamase-producing Enterobacterales (ESBLE) infections in non-urinary isolates

BACKGROUND: With increases in antimicrobial resistance, it is crucial that patients receive appropriate antimicrobial therapy in a timely manner. Advancements in rapid diagnostics offer the ability to identify resistant organisms quickly. However, this technology is not always accessible and relies on correct specimen collection. While awaiting new microbiology methods, it may be beneficial to identify risk factors associated with common types of resistance. Specifically, extended-spectrum β-lactamase-producing Enterobacterales (ESBLE) are a rising threat globally. OBJECTIVE: The primary objective of this retrospective case–control analysis was to identify factors associated with non-urinary ESBLE versus non-ESBLE infections. DESIGN/METHODS: Patient cultures were randomly selected based on type of culture (blood, bacterial, or exudate) and organism (E. coli, K. pneumoniae, or K. oxytoca) to provide a 1:1 ratio of ESBLE to non-ESBLE infections. Baseline demographics and potential risk factors (malignancy, cirrhosis, acute kidney injury (AKI), and diabetes) were collected for each patient encounter. RESULTS: In the univariate analysis, risk factors that achieved a significant difference included cirrhosis, AKI, presence of urinary catheter, presence of center venous catheter, history of an ESBLE infection, hospital-acquired infection, and recent fluoroquinolone, cephalosporin, or beta-lactam use. The multivariate analysis showed that four factors were independently associated with an ESBLE infection: cirrhosis, urinary catheter, central venous catheter, and history of ESBLE. Having a history of an ESBLE had the highest adjusted odds ratio (aOR 12.49; 95% CI 4.71–33.15, P < .001) of the four factors. CONCLUSIONS: These results demonstrate that there may be benefit in incorporating select risk factors into clinical decision support tools to identify patients at highest risk of ESBLE infection.