Outcomes and mortality risk scoring for infections caused by carbapenem-resistant Escherichia coli and Klebsiella pneumoniae

Abstract

Introduction: Carbapenem-resistant Enterobacterales (CRE) are becoming increasingly prevalent and have been associated with increased mortality. Due to the paucity of data from the region, we evaluated the risk factors and outcomes of infections caused by CRE at a tertiary care center in Lebanon.

Methodology: The study had three arms in a case-case-control design: patients with CRE infections, patients with infections due to ceftriaxone-resistant carbapenem-susceptible Enterobacterales (CSE), and uninfected controls (UC). Logistic regression was performed to identify risk factors uniquely associated with CRE. A CRE infection score was also created to assess the likelihood of having a CRE infection.

Results: We included 337 patients (112 CRE, 75 CSE, 150 UC). Predictors unique to CRE infection included recent surgery (Odds Ratio (OR) 25.7; 95% confidence interval (CI95 5.7-115.2), carbapenem use within 30 days (OR 19.1; CI95 3.3-109.6), and malignancy (OR 4.2; CI95 1.6-10.5). The mean CRE score was 4.2 ± 2.2 in the CRE group and 2.4 ± 2.4 in the CSE group (p < 0.001). Infection-related mortality was higher among CRE patients (63.6% vs. 20.0%; p = 0.015), and CRE was independently associated with all-cause in-hospital mortality.

Conclusions: We developed a scoring system that would allow risk stratification and would guide empiric antibiotic therapy. CRE infections were associated with a worse outcome compared to CSE infections.

Keywords: Carbapenem resistance; Enterobacterales; risk stratification.