Thirty-Day Mortality Associated With Carbapenemase-Producing Enterobacterales Bloodstream Infections at a Referral Hospital in Peru, 2020-2023.

Background: Bloodstream infections (BSIs) caused by carbapenemase-producing Enterobacterales (CPE) are associated with increased mortality rates. However, limited data exist in Latin America, particularly in regions where bla NDM is predominant. Methods: We conducted a retrospective cohort study of adult inpatients with Escherichia coli or Klebsiella pneumoniae BSI at a Peruvian referral hospital between 2020 and 2023. Patients were classified as CPE or non-CPE based on molecular testing. The outcome was 30-day all-cause mortality. Multivariable Cox regression was used to identify independent predictors of mortality, adjusting for confounders selected via a directed acyclic graph. Results: Among 506 patients, 97 (19.2%) had CPE BSIs, predominantly bla NDM (63.9%) and bla KPC (36.1%). Overall, the 30-day mortality rate was 27.3%, significantly higher in the CPE group (52.6% vs 21.3%; P < .001). In multivariable analysis, CPE infection remained independently associated with increased mortality (adjusted hazard ratio [aHR] 1.88; 95% CI 1.19-2.96). Other predictors included age ≥60 years (aHR 1.53), septic shock (aHR 2.93), pneumonia (aHR 1.70), and immunosuppression (aHR 1.72). Among CPE subtypes, Klebsiella pneumoniae Carbapenemase (KPC)-producers conferred the highest mortality risk (aHR 2.64). Concordant empirical antibiotic therapy was not significantly protective after adjustment. Conclusions: CPE BSIs were independently associated with increased 30-day mortality, with KPC-producing K pneumoniae posing the greatest risk. Despite the predominance of New Delhi Metallo-β-Lactamase (NDM) in our setting, these findings emphasize the clinical severity associated with different carbapenemase types, and the need to tailor interventions accordingly. Strengthening molecular surveillance and ensuring timely access to effective therapies remain critical priorities in NDM-endemic regions, such as Peru.