1609. The natural history of colonization with carbapenem-resistant Enterobacteriaceae: outcomes related to colonization
Session: Poster Abstract Session: Multidrug-Resistant Gram Negative Rods
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
  • KPCIDWeek2013_final.pdf (714.5 kB)
  • Background:

    Carbapenem-resistant Enterobacteriaceae (CRE) are becoming increasingly prevalent in U.S. healthcare facilities. Few reports detail the natural history of CRE colonization. We describe clinical outcomes of CRE infection and colonization, including serial surveillance cultures, in a cohort of CRE-colonized patients at the NIH Clinical Center, a 240-bed research hospital.


    Patients found to be colonized with CRE were followed closely and screened with surveillance cultures during return visits to monitor colonization status. Surveillance cultures collected from throat, groin, perirectal area, and stool were inoculated on KPC CHROMagar (Hardy Diagnostics). Suspicious colonies were identified by MALDI-TOF mass spectrometry and tested by KPC PCR and modified Hodge test. Clinical records were reviewed retrospectively to provide insight into the natural history of KPC colonization. 


    Among 22 patients identified with CRE colonization, 19 carried a single nosocomial strain of K. pneumoniae, 3 patients carried distinct strains of Klebsiella. Nine highly immunocompromised patients developed bacteremia with KPC-carrying Klebsiella a median of 11 days (range 2-37) after colonization was first detected. Seven patients died of bacteremia and two patients survived bacteremia but died of underlying illness. Among colonized patients who did not become infected, 6 died of underlying conditions and 1 has not yet returned for followup. We have collected surveillance cultures collected from 6 of the surviving colonized patients. One patient remains colonized after 507 days. Five patients’ cultures have reverted to negative after a mean of 5.2 sets of surveillance cultures over a median of 216 days (range 134-376). 


    CRE infections have a very high mortality rate among immunocompromised patients. All patients who had CRE bacteremia died, and no surviving patients have had CRE isolated from any clinical culture.  CRE colonization portends a poor prognosis, particularly among immunocompromised patients. Patients who do not develop infection can have prolonged CRE colonization that may clear over time.

    Brooke K. Decker, MD, Infectious Diseases/Critical Care Medicine, National Institutes of Health, Bethesda, MD, Amanda M. Heath, Clinical Center, National Institutes of Health, Bethesda, MD, David K. Henderson, MD, National Institutes of Health Clinical Center, NIH, Bethesda, MD and Tara N. Palmore, MD, National Institutes of Health Clinical Center and National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD


    B. K. Decker, None

    A. M. Heath, None

    D. K. Henderson, None

    T. N. Palmore, None

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.