Transmission of Extended-Spectrum ?-Lactamase-Producing Enterobacteriaceae by A Contaminated Duodenoscope

Contamination of duodenoscopes is a significant concern due to the transmission of multidrug-resistant organisms (MDROs) among patients who undergo endoscopic retrograde cholangiopancreatography (ERCP), resulting in outbreaks worldwide. In July 2020, it was determined that three different patients, all had undergone ERCP with the same duodenoscope, two were infected with blaCTX-M-15 encoding Citrobacter freundii, with one patient experiencing a bloodstream infection and the other a urinary tract infection, while another patient had bloodstream infection caused by blaSHV-12 encoding Klebsiella pneumoniae. After withdrawing the suspected duodenoscope, we initiated a comprehensive epidemiological investigation, encompassing initial and additional case finding, along with a thorough duodenoscope investigation. Screening of patients who had undergone ERCP with the implicated duodenoscope, as well as a selection of hospitalized patients who had ERCP with a different duodenoscope during the outbreak period, led to the discovery of three additional cases of colonization in addition to the three infections initially detected. No microorganisms were detected in eight routine culture samples retrieved from the suspected duodenoscope. Only after destructive dismantling of the duodenoscope, the forceps elevator was found to be positive for blaSHV-12 encoding K. pneumoniae which was identical to the isolates detected in three patients. This study highlights the importance of using NGS to monitor the transmission of multidrug-resistant organisms (MDROs) and demonstrates that standard scope cultures may fail to detect contaminated duodenoscopes.