title: Endoscopy supply water and final rinse testing: five years of experience.
abstract: BACKGROUND
  The penultimate stage in endoscope reprocessing is the final rinse with water following terminal disinfection. This requires a degree of microbiological and chemical control of the quality of the final rinse water.
  
  
  OBJECTIVE
  To report experience gained over five years of testing, reporting and managing the quality of final rinse water for endoscopic devices.
  
  
  METHODS
  Three endoscope reprocessing units, each comprising five endoscope washer-disinfectors (EWDs) supplied by two reverse osmosis (RO) water units, were subjected to weekly monitoring and control of final rinse water quality. EWDs were subjected to nightly thermal self-disinfection, and RO units were subjected to periodic sanitization with peracetic acid. Final rinse water samples were processed periodically for total viable counts (TVCs), Pseudomonas spp., endotoxins, conductivity, environmental mycobacteria and Legionella spp.
  
  
  RESULTS
  Over the five-year study period (2008-2013), no Pseudomonas spp., environmental mycobacteria or Legionella spp. were isolated from endoscopy rinse water. All conductivity readings were below 30 μs/cm. Endotoxin levels fluctuated over the recommended cut-off of 0.25 EU/mL, with no correlation with TVCs. Trend analysis of TVCs established alert and action limits. Apart from the supply water of one EWD becoming contaminated with Aspergillus spp., there have been no interruptions to operational capacity of the endoscope reprocessing units.
  
  
  CONCLUSIONS
  Quality control principles coupled with appropriate thermal and chemical disinfection of EWDs resulted in the achievement of microbiological standards for final rinse water. A co-ordinated team approach between the microbiology department, infection control department, endoscope unit managers and estates department is required to achieve this degree of success.
authors.affiliation: Bacteriology Department, Glasgow Royal Infirmary, Glasgow, UK. Electronic address: amarek@nhs.net.
authors.forename: A
authors.initials: A
authors.lastname: Marek
authors.affiliation: Glasgow Dental School, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
authors.forename: A
authors.initials: A
authors.lastname: Smith
authors.affiliation: Endoscopy Reprocessing Unit, Stobhill Ambulatory Care and Diagnostics Centre, Glasgow, UK.
authors.forename: M
authors.initials: M
authors.lastname: Peat
authors.affiliation: Endoscopy Reprocessing Unit, Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: A
authors.initials: A
authors.lastname: Connell
authors.affiliation: Endoscopy Reprocessing Unit, Victoria Ambulatory Care and Diagnostics Hospital, Glasgow, UK.
authors.forename: I
authors.initials: I
authors.lastname: Gillespie
authors.affiliation: Estates Department, Inverclyde, Glasgow, UK.
authors.forename: P
authors.initials: P
authors.lastname: Morrison
authors.affiliation: Estates Department, Cowlairs, Glasgow, UK.
authors.forename: A
authors.initials: A
authors.lastname: Hamilton
authors.affiliation: Estates Department, Cowlairs, Glasgow, UK.
authors.forename: D
authors.initials: D
authors.lastname: Shaw
authors.affiliation: Estates Department, Cowlairs, Glasgow, UK.
authors.forename: A
authors.initials: A
authors.lastname: Stewart
authors.affiliation: Infection Control Department, Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: K
authors.initials: K
authors.lastname: Hamilton
authors.affiliation: Bacteriology Department, Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: I
authors.initials: I
authors.lastname: Smith
authors.affiliation: Bacteriology Department, Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: A
authors.initials: A
authors.lastname: Mead
authors.affiliation: Health Facilities Scotland, Glasgow, UK.
authors.forename: P
authors.initials: P
authors.lastname: Howard
authors.affiliation: Health Facilities Scotland, Glasgow, UK.
authors.forename: D
authors.initials: D
authors.lastname: Ingle
mesh_terms: D015169:Colony Count, Microbial; D003428:Cross Infection; D004203:Disinfection / Q000379:methods*; D019723:Endoscopes / Q000382:microbiology*; D004724:Endoscopy; D004731:Endotoxins / Q000032:analysis; D004866:Equipment Contamination / Q000517:prevention & control*; D017053:Infection Control / Q000379:methods; D007875:Legionella / Q000302:isolation & purification; D050296:Microbial Viability; D009161:Mycobacterium / Q000302:isolation & purification; D011549:Pseudomonas / Q000302:isolation & purification; D011786:Quality Control; D014881:Water Supply / Q000592:standards*
chemical_list: D004731:Endotoxins
keywords: Endoscopy; Final rinse water; Legionella spp.; Pseudomonas spp.; Total viable counts