391. Carbapenem-Resistant Enterobacteriaceae (CRE): A Statewide Survey of Detection Methods and Prevalence in Massachusetts Hospitals
Session: Poster Abstract Session: Gram Negative Infection - Epidemiology and Prevention
Friday, October 21, 2011
Room: Poster Hall B1
Background: Carbapenem-resistant Enterobacteriaceae (CRE) have emerged rapidly worldwide; however, local prevalence is unknown. Given the difficulty identifying and confirming carbapenemase activity, the current burden of CRE may be underestimated. Moreover, recent changes in the Clinical Laboratory and Standards Institute (CLSI) recommend lower MIC breakpoints to detect CREs, yet it is unclear how widely these guidelines are implemented and what effect they have on CRE detection rates. Methods: Online surveys were sent to all 70 Massachusetts hospital microbiology laboratories and corresponding infection prevention teams. Standardized questions were used to estimate the proportion of hospitals detecting CREs in 2010 and to analyze current microbiological methods for CRE detection. The data was analyzed using SPSS. Results: Of 70 hospitals surveyed, 45 responses from microbiology laboratories and 49 responses from infection prevention teams were received; 63 hospitals responded to either or both surveys, representing 90% of Massachusetts hospitals. All areas of the state reported detection of CREs, with 49% of responding hospitals detecting CREs; 33% reported no CREs; 13% did not know; and 5% did not answer the question. Teaching hospitals were more likely to report CREs (75%) than non-teaching centers (46%) (p=0.036). Of the 45 responding microbiology laboratories, 51% reported following the new CLSI guidelines, yet only one hospital correctly reported use of the >0.5 mcg/ml ertapenem MIC to prompt consideration of a CRE. Finally, the lower the ertapenem MIC cutoff used for CRE detection the more likely the institution was to recognize a CRE (Spearman rank order correlation coefficient: -0.489, p=0.013). Conclusion: We report the first statewide survey of CRE prevalence, demonstrating CREs in nearly half of Massachusetts hospitals, including rural, urban, teaching, and non-teaching settings. Our measure of CRE prevalence is likely an underestimate, given most institutions use higher MIC cutoffs than are now recommended to prompt CRE consideration. Application of current CLSI guidelines will provide a more accurate picture of the burden of infection due to CRE and guide urgently needed infection control interventions.

Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Evangeline Thibodeau, MD1, Robert Duncan, MD, MPH2, David Snydman, MD, FIDSA1, Barbara Bolstorff, MPH3, Johanna Vostok, MPH3, Kerri Barton, MPH3 and Alfred DeMaria Jr., MD3, (1)Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, MA, (2)Lahey Clinic, Burlington, MA, (3)Massachusetts Department of Public Health, Jamaica Plain, MA


E. Thibodeau, Merck: Research Grant Recipient, Research grant

R. Duncan, None

D. Snydman, Merck: Research Contractor, Grant recipient
Pfizer: Research Contractor, Research grant
Optimer: Research Contractor, Research grant and Research support
Cubist: Research Contractor and Speaker's Bureau, Research grant, Research support and Speaker honorarium
Genentech: Consultant, Grant Investigator, Scientific Advisor and Speaker's Bureau, Consulting fee, Research grant and Speaker honorarium
CSL Behring: Consultant and Speaker's Bureau, Consulting fee and Speaker honorarium
Novartis: Scientific Advisor, Consulting fee
Millenium: Data Safety Monitoring Board, Consulting fee
Genzyme: Data Safety Monitoring Board, Consulting fee
Mass Biologic Laboratories: Data Safety Monitoring Board, Consulting fee
Boeringer-Ingelheim: Consultant, Consulting fee

B. Bolstorff, None

J. Vostok, None

K. Barton, None

A. DeMaria Jr., None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.