Carbapenemresistant Klebsiella pneumoniae (KPC‐KP) has become a major nosocomial pathogen over the past decade. The first KPC‐KP was isolated in an Emory University–affiliated hospital in 2006, and since then the number of isolates has increased annually, including 36 isolates in 2009. The treatment of this multidrug‐resistant infection is challenging, given that KPC‐KP confers resistant to virtually all commonly using antibiotics. Determination of risk factors for infection/ colonization remains critical in order to develop effective measures to prevent spread.
To detect risk factors for acquisition of KPC‐KP, we conducted a retrospective case–control study across the 2 Emory University–affiliated teaching hospitals. A total of 30 KPC‐KP isolates were identified by the Emory University laboratory registry from 2006 through 2008. All patients with KPC‐KP‐positive cultures (defined as cases) were randomly matched with controls (1:4) by initial culture date, sex, and age. The exact conditional logistic regression method was used for statistical analysis. Pulsed‐field gel electrophoresis (PFGE) was used for molecular subtyping for detection of genetic relatedness among the isolates.
Charts were reviewed from 30 cases and 120 controls. Statistically significant risk factors for acquisition of KPC‐KP included prehospital antibiotic use (P < 0.005), in‐hospital use of 2 or more antibiotics (P < 0.005), poor performance status defined by the Karnofsky performance scale index (P < 0.002), multiple comorbidities calculated using the Charlson comorbidity index score (P < 0.02), malnutrition (P < 0.03), and nursing home residence (P < 0.017), which significantly increase risk for this infection. ICU exposure prior to KPC‐KP isolation (P < 0.03), prolonged hospitalization (P < 0.04), and multiple surgical procedures (P < 0.03) also increased the risk for KPC‐KP acquisition. Molecular epidemiology investigation conducted by PFGE revealed that more than 90% of KPC‐KP isolates shared similar PFGE patterns (>85% band similarity) and suggested interhospital transmission.
The results of our study suggest that prolonged hospitalization and prior antibiotic use increases the risk of acquisition of KPC‐KP. The patients most vulnerable to KPC‐KP include those with multiple comorbidities and functional impairment. Because interhospital transmissions occur, implementation of infection control practices are necessary to prevent spread among hospitalized patients.
K. Kobaidze ‐ none; J. Jacob ‐ none; B. Ribner ‐ none; J. Steinberg ‐ none; E. Burd ‐ none; D. W. Flanders ‐ none