Seventeen USA cases associating exposure to a duodenoscope with infections or an outbreak of CRE or a related MDRO (listed in chronological order)
| Case number | Approximate year infections, outbreak began | Reference number | Medical facility's state in USA | Type of resistant bacteria (eg, CRE) | Number of patients infected (or testing positive) | Number of patients who expired* | Sealed or unsealed duodenoscope model? | Were bacteria† recovered from a duodenoscope? | Was HLD being performed? | Was duodenoscope reportedly reprocessed according to manufacturer IFUs? | Case's possible cause(s) | Case's implemented measure(s), response |
| 1 | 2012 | 7 22–24 | PA | CRE (Klebsiella pneumoniae) | 10-13 | NR | Sealed | Yes | Yes | Yes | Ineffective duodenoscope reprocessing reported. | Began using EO gas to sterilize the duodenoscope, which reportedly terminated the outbreak. Periodic endoscope culturing performed. |
| 2 | 2012 | 7 12 22 | WA | CRE (AmpC-producing E. coli) | 32 | 11 | Sealed and unsealed | Yes | Yes | Yes | Several duodenoscopes reported to have at least one "critical defect" or "critical abnormality" requiring repair. Difficulty cleaning the elevator channel reported. | Began culturing, quarantining duodenoscopes. |
| 3 | 2012 | 7 22 | NY | CRE (K. pneumoniae) | 15 | NA | Sealed and unsealed | Yes | Yes | NR | NR | Began using EO gas to sterilize the duodenoscope. |
| 4 | 2013 (2008‡) | 29 | FL§ | CRE (K. pneumoniae) | 7 | At least 1 | NR | Yes | NR | No | Inadequate cleaning of the duodenoscope's terminal part containing the elevator mechanism reported. | Received instruction on the correct cleaning and handling of duodenoscopes. Began performing additional manual cleaning of the duodenoscope's distal end using a brush. |
| 5 | 2013 | 7–10 17 22 | IL | CRE (NDM-1-producing E. coli) | 35 | 2 | Sealed | Yes | Yes | Yes | Difficulty cleaning the duodenoscope due to its complex design reported. | Began using EO gas to sterilize the duodenoscope, which reportedly terminated the outbreak. |
| 6 | 2013 | 7 16 | WI | CRE (NDM-1-producing E. coli) | 3 | NR | Sealed | No | Yes | Yes | Not determined. | Began using EO gas to sterilize the duodenoscope, which reportedly terminated the outbreak. |
| 7 | 2013 | 22 27 | CA | MDRO (Pseudomonas aeruginosa) | 16 | As many as 11 | Sealed and unsealed | Yes | Yes | No | Ineffective duodenoscope reprocessing hypothesised possibly due to several factors including the device's design reported. Some duodenoscope reprocessing and storage lapses reported. Inadequate maintenance of automated endoscope reprocessors reported. | Implicated duodenoscopes removed from use. Began reprocessing all duodenoscopes twice. |
| 8 | 2014 | 7 | IL | CRE | 3 | NR | Sealed | Yes | NR | NR | Not determined. | NR |
| 9 | 2014 | 7 20 22 | CA | CRE (OXA-232-producing K. pneumoniae) | 16 | 6 | Sealed | No | Yes | Yes | Ineffective duodenoscope reprocessing reported. | Began supplementing manual cleaning and HLD with EO gas sterilization of duodenoscopes performed off-site. Implicated duodenoscopes removed from use. |
| 10 | 2015 | 7 22 50 | NC | CRE | 18 | 1 | Sealed | No | NR | NR | Not determined. | Began using EO gas to sterilize the duodenoscope. |
| 11 | 2015 (2008¶) | 28 | USA§ | CRE (K. pneumoniae) | 7 | NR | Unsealed | Yes | NR | No | Improper drying and storage of the duodenoscope reported. | Began routine culturing and testing of new duodenoscopes prior to and after each use. Implicated duodenoscopes removed from use. |
| 12 | 2015 | 7 | PA | CRE (K. pneumoniae) | 3 | NR | Sealed | Yes | NR | NR | Not determined. | NR |
| 13 | 2015 | 51 | CO | MDRO (ESBL-producing E. coli**) | 9 | 3 | Sealed | No | NR | NR | Not determined. | NR |
| 14 | 2015 | 7 | MA | MDRO (ceftriaxone-resistant E. coli) | 3 | NR | Sealed | NR | NR | NR | Not determined. | NR |
| 15 | 2017 | 26 | MA†† | MDRO (mcr-1-positive K. pneumoniae) | 2 | NR | Sealed | Yes | Yes | Yes | Ineffective duodenoscope reprocessing reported. Persistant contamination of duodenoscopes "most likely due to a distal cap defect" reported. | Implicated duodenoscope removed from use and returned to the manufacturer for evaluation. |
| 16 | 2017 | 33 | USA†† | MDRO (mcr-1-positive bacteria) | 2 | NR | Sealed | Not conclusive | NR | NR | Not determined. | An implicated duodenoscope was sequestered. |
| 17 | 2018 | 52 | USA | CRE (and other bacteria) | 30 | 2 | Unsealed | NR | Yes | No | Pre-cleaning of duodenoscopes reported to be delayed at times ("for over one-hour"). During periods of high volume, the number of certain cleaning adapters reportedly could be insufficient. | NR |
Note: This list is not inclusive of all cases since 2012.
*The infections were not necessarily the cause of the deaths and could have been due to other underlying medical problems (eg, cancer, liver failure).
†The bacteria collected from the tested duodenoscope may be, but are not necessarily, the outbreak’s strain.
‡This outbreak occurred in 2008, but its details were not published until 2013.
§Some of the traits of these two cases are similar, although their relationship, if any, is unknown, unclear and could be coincidental (ie, case number 4 and 11).
¶These infections occurred in 2008 and 2009 and were reported to the FDA in 2015.
**ESBLs, or extended-spectrum beta-lactamases, are enzymes that bacteria, such as E. coli, may produce rendering the bacteria resistant to certain antibiotics.
††Some of the traits of these two cases are similar, although their relationship, if any, is unknown, unclear and could be coincidental (ie, case number 15 and 16).
AERs, automated endoscope reprocessors; CRE, carbapenem-resistant Enterobacteriaceae; EO, ethylene oxide; HLD, high-level disinfection; IFUs, instructions for use; MDRO, multidrug-resistant organism; NA, not applicable; NR, not reported.