Risk of infection transmission in curvilinear array echoendoscopes: results of a prospective reprocessing and culture registry

Gastrointest Endosc. 2017 Feb;85(2):390-397.e1. doi: 10.1016/j.gie.2016.07.049. Epub 2016 Jul 28.


Background and aims: The complex design of the elevator mechanism in duodenoscopes has been recognized as a challenge for disinfection and recently implicated as a potential source of persistent bacterial contamination. Curvilinear array (CLA) echoendoscopes also have an elevator mechanism; however, there are no recommendations or data regarding the risk of persistent bacterial contamination of echoendoscopes. Here we hoped to determine the yield of microbial growth with routine bacterial surveillance cultures of reprocessed CLA echoendoscopes.

Methods: Beginning in February 2015 to February 2016, CLA echoendoscopes at a single tertiary care center underwent prospective bacterial surveillance cultures after reprocessing. Any growth of gram-negative bacilli was considered to be critical. Echoendoscopes with a positive result underwent quarantine followed by repeat disinfection and culture.

Results: During the study period, 540 cultures were obtained; 521 (96.5%) were primary cultures obtained from 18 CLA echoendoscopes. Twenty-two primary cultures (4.2%) were positive for gram-negative bacilli after high-level disinfection reprocessing. Eleven different bacteria were isolated: Klebsiella pneumoniae, Citrobacter freundii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca, Sphingomonas paucimobilis, Acinetobacter baumanii, Enterobacter cloacae, Hafnia alvei, Pseudomonas putida, and Stenotrophomonas maltophilia. Antibiotic sensitivity data on 19 of 24 bacteria (79.2%) isolated from positive primary cultures revealed no documented cases of carbapenem-resistant enterobacteriaceae, cephalosporin-resistant-Klebsiella, or multidrug-resistant Acinetobacter. There have been no documented cases of patient-to-patient transmission.

Conclusions: After following standard high-level disinfection and reprocessing, CLA echoendoscopes can remain culture positive for high-concern organisms. Recommendations regarding infection risk should take into consideration elevator-containing echoendoscopes in addition to duodenoscopes to ensure patient safety and endoscope reprocessing efficacy.

MeSH terms

  • Acinetobacter baumannii / isolation & purification
  • Citrobacter freundii / isolation & purification
  • Cross Infection / epidemiology*
  • Culture Techniques*
  • Disinfection*
  • Endosonography / instrumentation*
  • Enterobacter cloacae / isolation & purification
  • Equipment Contamination*
  • Hafnia alvei / isolation & purification
  • Humans
  • Klebsiella oxytoca / isolation & purification
  • Klebsiella pneumoniae / isolation & purification
  • Microbial Sensitivity Tests
  • Prospective Studies
  • Pseudomonas aeruginosa / isolation & purification
  • Pseudomonas putida / isolation & purification
  • Registries*
  • Sphingomonas / isolation & purification
  • Stenotrophomonas maltophilia / isolation & purification