Endoscope-Associated Multidrug-Resistant Escherichia coli Outbreak — King County, Washington, 2012–2014
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.
C. Baliga, None
P. Verma, None
S. Weissman, None
M. Gluck, None
A. S. Ross, None
J. Duchin, None