Multidrug-Resistant Klebsiella Pneumoniae Outbreak after Endoscopic Retrograde Cholangiopancreatography

Background and study aims: Infection is a recognized complication of endoscopic retrograde cholangiopancreatography (ERCP). We describe the epidemiologic and molecular investigations of an outbreak of ERCP-related severe nosocomial infection due to Klebsiella pneumoniae producing extended-spectrum beta-lactamase (ESBL). Patients and methods: We conducted epidemiologic and molecular investigations to identify the source of the outbreak in patients undergoing ERCP. We carried out reviews of the medical and endoscopic charts and microbiological data, practice audits, surveillance cultures of duodenoscopes and environmental sites, and molecular typing of clinical and environmental isolates. Results: Between December 2008 and August 2009, 16 patients were identified post-ERCP with Klebsiella pneumoniae that produced extended-spectrum beta-lactamase type CTX-M-15. There were 8 bloodstream infections, 4 biliary tract infections, and 4 cases of fecal carriage. The microorganism was isolated only from patients who had undergone ERCP. Environmental investigations found no contamination of the washer-disinfectors or the surfaces of the endoscopy rooms. Routine surveillance cultures of endoscopes were repeatedly negative during the outbreak but the epidemic strain was finally isolated from one duo-denoscope by flushing and brushing the channels. Molecular typing confirmed the identity of the clinical and environmental strains. Practice audits showed that manual cleaning and drying before storage were insufficient. Strict adherence to reprocessing procedures ended the outbreak. Conclusions: The endoscopes used for ERCP can act as a reservoir for the emerging ESBL-producing K. pneumoniae. Regular audits to ensure rigorous application of cleaning, high-level disinfection, and drying steps are crucial to avoid contamination.