Giannella M, et al. - In this multicenter prospective matched case–control study, researchers sought risk factors for carbapenem-resistant Klebsiella pneumoniae (CR-KP) bloodstream infection (BSI) among carriers. They compared 143 CR-KP BSIs with 572 controls with no documented infection during their hospitalization. The independent risk factors for CR-KP BSI development among CR-KP rectal carriers included admission to the intensive care unit (ICU), abdominal invasive procedure, chemotherapy/radiation therapy, and number of additional colonization sites. Based on these four independent variables, they developed a CR-KP BSI risk score ranging from 0 to 28. The model exhibited a sensitivity, specificity, positive predictive value and negative predictive value of 93%, 42%, 29% and 93%, respectively, at a cut-off of ≥2. In this large cohort of CR-KP rectal carriers, the strongest predictor of BSI development was colonization at multiple sites with CR-KP.