Prevalence, risk factors and outcomes of carbapenem-resistant Klebsiella pneumoniae bloodstream infection

Background: The long-term epidemiological surveillance of carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infection (BSI) is limited in China, and the impact of carbapenem resistance on mortality remains unknown. This study aimed to investigate the prevalence, factors and outcomes of CRKP BSI, and examine the attributable mortality of carbapenem resistance. Methods This retrospective study enrolled 87 patients with CRKP BSI and 321 patients with carbapenem-susceptible Klebsiella pneumoniae (CSKP) BSI from 2015 to 2020. Multivariate logistic regression was performed to identify risk factors for infection and mortality. Stabilized inverse probability of treatment weighting was applied to balance covariates. Cox regression and Kaplan-Meier curves were used to estimate the attributable mortality of carbapenem resistance. Results An alarming increasing trend of CRKP BSI was observed during the six years. Longer hospitalization stay, intensive care unit stay, blood purification and antibiotic exposure were risk factors for CRKP BSI, whereas primary BSI and underlying diabetes were factors for CSKP BSI. The crude 30-day mortality of CRKP BSI was independently associated with age ≥ 55 years, underlying hematological malignancies and blood purification, while the infection source from skin and soft tissue, urinary catheter and underlying chronic obstructive pulmonary disease were predictors for CSKP BSI. The hazard ratios reflecting the impact of carbapenem resistance on 30-day mortality was 1.586 (0.791–3.182). Conclusions The 30-day mortality was not attributed to carbapenem resistance in KP BSI. Infection control policies for severely ill patients with prolonged hospitalizations and intensive care and patients with blood purification should be strengthened for CRKP BSI management.