Risk factors for clinical treatment failure regarding carbapenem-resistant Enterobacterales in the southwestern United States

Background

Rates of carbapenem resistant Enterobacterales (CRE)-related infections in the United States have continued to rise, leading to significant morbidity and mortality. Klebsiella pneumoniae carbapenemases (KPC) have been the most common carbapenemase in the United States; over time, however, a shift has occurred in some regions.

Methods

A multicenter, retrospective observational study was performed across a large-scale healthcare system of 33 acute care hospitals in the southwestern United States, primarily Arizona. Patients were included if they were ≥ 18 years old with resistance to at least one carbapenem from January 1st, 2023 to July 31st, 2023.

Results

Among 169 included patients, the most common CRE species was Klebsiella pneumoniae (82 %) with the most common identified carbapenemase being metallo beta lactamase (MBL) (76 %), the majority of which were New Delhi metallo-beta-lactamases (NDMs). Multivariable logistic regression was performed to determine risk factors for treatment failure regarding CRE infections. This model found renal replacement therapy [OR 2.44 (95 % CI 1.04–5.71)], prior hospitalization within 90 days of index culture [OR 2.69 (95 % CI 1.12–6.47), and admission to the ICU [OR 5.55 (95 % CI 2.58–11.93)] to be statistically significant risk factors for treatment failure.

Conclusions

Our study highlights the alarming rise of NDM-producing CRE’s in the southwestern US, primarily Arizona, along with the importance of closely assessing patient risk factors in view of deciding on appropriate empiric therapy.