Program Schedule

Endoscope-Associated Multidrug-Resistant Escherichia coli Outbreak King County, Washington, 20122014

Session: Oral Abstract Session: Late Breaker Oral Abstracts
Saturday, October 11, 2014: 11:20 AM
Room: The Pennsylvania Convention Center: 105-AB
Background: We identified an outbreak of AmpC–producing Escherichia coli infections resistant to cefoxitin and third-generation cephalosporins and with phenotypic carbapenem resistance (CRE) among 7 patients who had undergone endoscopic retrograde cholangiopancreatography (ERCP) at Hospital A during November 2012–August 2013. PCR testing for carbapenemase genes was negative. Gene sequencing revealed a shared novel mutation in a blaCMY gene encoding CMY-2 and a distinctive fumC/fimH typing profile. We report the findings of our investigation.

Method: We reviewed laboratory results, medical records, endoscopy reports, and endoscope reprocessing procedures. We obtained cultures from endoscopes after reprocessing and from environmental samples. We conducted PFGE and PCR with gene sequencing on AmpC E. coli isolates from patients and endoscopes. Cases were patients with AmpC E. coliinfection resistant to cefoxitin and 3rd-generation cephalosporins and identical fumC, fimH and blaCMY-2 alleles.

Result: We selected 39 archived AmpC E. coli patient isolates for testing based on clinical similarity to initial cases; in total, 30 met the case definition, including 10 with carbapenem resistance. All cases had complicated biliary disease and had at least 1 ERCP at Hospital A. Isolates fell into 2 closely related PFGE clusters. Mortality at 30 days was 23% for all cases and 50% for CRE cases. Two (25%) of 8 reprocessed ERCP scopes harbored AmpC E. coli that matched case isolates by PFGE. Environmental cultures were negative. No breaches in infection control were identified. Endoscopic reprocessing exceeded manufacturer’s recommended cleaning guidelines.

Conclusion: An outbreak of a novel AmpC E. coli strain occurred among patients undergoing ERCP for severe biliary disease. Although endoscopes had been reprocessed according to industry standards, we identified contaminated endoscopes that might have facilitated health care transmission. Recommended reprocessing guidelines should be reevaluated.

Kristen Wendorf, MD, MS1, Meagan Kay, DVM, MPVM2, Christopher Baliga, MD3, Punam Verma, PhD4, Scott Weissman, MD5, Michael Gluck, MD3, Andrew S. Ross, MD3 and Jeffrey Duchin, MD, FIDSA6, (1)Epidemiology Workforce Branch, Centers for Disease Control and Prevention, Atlanta, GA, (2)Communicable Diseases and Immunizations, Public Health - Seattle & King County, Seattle, WA, (3)Virginia Mason Medical Center, Seattle, WA, (4)Microbiology, Virginia Mason Medical Center, Seattle, WA, (5)Seattle Childrens Research Institute, Seattle, WA, (6)Public Health, Public Health-Seattle & King County, Seattle, WA


K. Wendorf, None

M. Kay, None

C. Baliga, None

P. Verma, None

S. Weissman, None

M. Gluck, None

A. S. Ross, None

J. Duchin, None

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