title: Surveillance cultures of samples obtained from biopsy channels and automated endoscope reprocessors after high-level disinfection of gastrointestinal endoscopes.
abstract: BACKGROUND
  The instrument channels of gastrointestinal (GI) endoscopes may be heavily contaminated with bacteria even after high-level disinfection (HLD). The British Society of Gastroenterology guidelines emphasize the benefits of manually brushing endoscope channels and using automated endoscope reprocessors (AERs) for disinfecting endoscopes. In this study, we aimed to assess the effectiveness of decontamination using reprocessors after HLD by comparing the cultured samples obtained from biopsy channels (BCs) of GI endoscopes and the internal surfaces of AERs.
  
  
  METHODS
  We conducted a 5-year prospective study. Every month random consecutive sampling was carried out after a complete reprocessing cycle; 420 rinse and swabs samples were collected from BCs and internal surface of AERs, respectively. Of the 420 rinse samples collected from the BC of the GI endoscopes, 300 were obtained from the BCs of gastroscopes and 120 from BCs of colonoscopes. Samples were collected by flushing the BCs with sterile distilled water, and swabbing the residual water from the AERs after reprocessing. These samples were cultured to detect the presence of aerobic and anaerobic bacteria and mycobacteria.
  
  
  RESULTS
  The number of culture-positive samples obtained from BCs (13.6%, 57/420) was significantly higher than that obtained from AERs (1.7%, 7/420). In addition, the number of culture-positive samples obtained from the BCs of gastroscopes (10.7%, 32/300) and colonoscopes (20.8%, 25/120) were significantly higher than that obtained from AER reprocess to gastroscopes (2.0%, 6/300) and AER reprocess to colonoscopes (0.8%, 1/120).
  
  
  CONCLUSIONS
  Culturing rinse samples obtained from BCs provides a better indication of the effectiveness of the decontamination of GI endoscopes after HLD than culturing the swab samples obtained from the inner surfaces of AERs as the swab samples only indicate whether the AERs are free from microbial contamination or not.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Niao-Sung District, Taiwan. c471026@ms6.hinet.net
authors.forename: King-Wah
authors.initials: KW
authors.lastname: Chiu
authors.forename: Ming-Chao
authors.initials: MC
authors.lastname: Tsai
authors.forename: Keng-Liang
authors.initials: KL
authors.lastname: Wu
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Chiu
authors.forename: Ming-Tzung
authors.initials: MT
authors.lastname: Lin
authors.forename: Tsung-Hui
authors.initials: TH
authors.lastname: Hu
mesh_terms: D001419:Bacteria / Q000302:isolation & purification; D001706:Biopsy / Q000379:methods*; D004203:Disinfection / Q000295:instrumentation / Q000379:methods*; D020776:Endoscopes, Gastrointestinal / Q000382:microbiology*; D006801:Humans; D011446:Prospective Studies