title: A pilot study on using chlorine dioxide gas for disinfection of gastrointestinal endoscopes.
abstract: OBJECTIVE
  This pilot study of employing chlorine dioxide (CD) gas to disinfect gastrointestinal endoscopes was conducted to meet the expectations of many endoscopy units in China for a high-efficiency and low-cost disinfectant.
  
  
  METHODS
  An experimental prototype with an active circulation mode was designed to use CD gas to disinfect gastrointestinal endoscopes. One type of testing device composed of polytetrafluoroethylene (PTFE) tubes (2 m long, inner diameter 1 mm) and bacterial carrier containers was used to simulate the channel of the endoscope. PTFE bacterial carriers inoculated with Bacillus atrophaeus with or without organic burden were used to evaluate the sporicidal activity of CD gas. Factors including exposure dosage, relative humidity (RH), and flow rate (FR) influencing the disinfection effect of CD gas were investigated. Moreover, an autoptic disinfecting test on eight real gastrointestinal endoscopes after clinical use was performed using the experimental prototype.
  
  
  RESULTS
  RH, exposure dosage, organic burden, and the FR through the channel significantly (P<0.05) affected the disinfection efficacy of CD gas for a long and narrow lumen. The log reduction increased as FR decreased. Treatment with 4 mg/L CD gas for 30 min at 0.8 L/min FR and 75% RH, resulted in complete inactivation of spores. Furthermore, all eight endoscopes with a maximum colony-forming unit of 915 were completely disinfected. The cost was only 3 CNY (0.46 USD) for each endoscope.
  
  
  CONCLUSIONS
  The methods and results reported in this study could provide a basis for further studies on using CD gas for the disinfection of endoscopes.
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yi
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, China.
authors.forename: Li-Mei
authors.initials: LM
authors.lastname: Hao
authors.affiliation: Department of Digestive Endoscopy, General Hospital of Shenyang Military Region, Shenyang 110840, China.
authors.forename: Shu-Ren
authors.initials: SR
authors.lastname: Ma
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, China.
authors.forename: Jin-Hui
authors.initials: JH
authors.lastname: Wu
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, China.
authors.forename: Song
authors.initials: S
authors.lastname: Lin
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, China.
authors.forename: Zong-Xing
authors.initials: ZX
authors.lastname: Zhang
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, China.
authors.forename: Jian-Cheng
authors.initials: JC
authors.lastname: Qi
mesh_terms: D017606:Chlorine Compounds / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D020776:Endoscopes, Gastrointestinal; D006801:Humans; D010087:Oxides / Q000494:pharmacology*; D010865:Pilot Projects; D013171:Spores, Bacterial / Q000187:drug effects
chemical_list: D017606:Chlorine Compounds; D010087:Oxides; C025109:chlorine dioxide
keywords: Bacillus atrophaeus; Chlorine dioxide; Gaseous disinfectant; Gastrointestinal endoscope; Long and narrow channel