424. Superiority of Remnant Clostridium difficile Diarrhea Specimens in Detecting Carbapenem-Resistant Enterobacteriaceae (CRE) Colonization in a Tertiary Care Hospital with Low Endemicity
Session: Poster Abstract Session: HAI: Epidemiologic Methods
Thursday, October 5, 2017
Room: Poster Hall CD
Background: CRE have emerged as a significant cause of healthcare associated infections (HAI) resulting in significant morbidity and mortality. Identification of CRE colonized and/or infected patients early during care enables implementation of comprehensive infection control measures that limit spread and likely reduce the risk of CRE mediated HAI. Hospitals in areas where CRE is endemic have instituted universal surveillance programs to limit risk, typically employing perianal/perirectal swabs or stool. In our facility, CRE isolation from clinical specimens is so infrequent that a universal surveillance program would not be cost effective. Consequently, in facilities with low CRE prevalence, a targeted approach may be more effective at limiting the risk of CRE HAI. Prior antibiotic receipt is among the most prevalent predictors of CRE carriage and/or infection. Thus, the use of remnant Clostridium difficile diarrhea specimens to assess CRE carriage may be more effective than a universal surveillance program.

Methods: We compared remnant diarrhea specimens submitted for C difficile toxin PCR (n = 400 patients) and remnant VRE perianal swabs (n = 400 patients) to determine the superiority of one specimen type over the other for CRE carriage. Specimens were analyzed using both the disk method and broth method recommended by CDC. Carbapenem resistance was confirmed by ertapenem and meropenem disk diffusion testing. Putative ertapenem resistant isolates were identified by Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF).

Results: Two percent of the patients (8/400) from the universal surveillance arm (VRE) were found to harbor CRE. Six percent of the patients (24/400) from the targeted surveillance arm (C. difficile) were found to harbor CRE. This difference was significant (p value of <0.0039) enabling us to conclude that use of targeted specimens was superior in the ability to identify CRE from facilities with low clinical incidence of these microbes.

Conclusion: Use of targeted surveillance through screening remnant C. difficile diarrhea specimens was significantly better in its ability to detect CRE colonized patients than was universal surveillance using remnant VRE perianal swabs.

Fadyah Albalawi, B.S., MLT, Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, Lisa L Steed, PhD, Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC and Michael G Schmidt, PhD, Microbiology and Immunology, Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC


F. Albalawi, None

L. L. Steed, None

M. G. Schmidt, None

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