Predictive Models for Identification of Hospitalized Patients Harboring KPC-Producing Klebsiella pneumoniae.

The production of Klebsiella pneumoniae (Kp) carbapenemases (KPCs) by Enterobacteriaceae has become a significant problem in recent years.To identify factors that could predict isolation of KPC-Kp in clinical samples from hospitalized patients, we conducted a retrospective, matched (1:2) case-control studies in five large Italian hospitals. The case cohort consisted of adult inpatients whose hospital stay included at least one documented isolation of a KPC-Kp strain from a clinical specimen. For each case enrolled, we randomly selected two matched controls with no KPC-Kp-positive cultures of any type during their hospitalization. Matching involved hospital, ward, and month/year of admission, as well as time at risk for KPC-Kp isolation. A subgroup analysis was also carried out to identify risk factors specifically associated with true KPC-Kp infection.During the study period, KPC-Kp was isolated from clinical samples of 657 patients; 426 of these cases appeared to be true infections. Independent predictors of KPC-Kp isolation were recent admission to ICU, indwelling urinary catheter, central venous catheter (CVC), and/or surgical drain, ≥ 2 recent hospitalizations, hematological cancer, and recent fluoroquinolone and/or carbapenem therapy. Charlson Index ≥3, indwelling CVC, recent surgery, neutropenia, ≥2 recent hospitalizations, and recent fluoroquinolone and/or carbapenem therapy were independent risk factors for KPC-Kp infection. Models developed to predict KPC-Kp isolation and KPC Kp infection displayed good predictive power with the areas under the receiver-operating characteristic curves of 0.82 (95% CI, 0.80-0.84) and 0.82 (95% CI, 0.80-0.85), respectively.This study provides novel information, which might be useful for the clinical management of patients harboring KPC Kp and for controlling the spread of these organisms.