Transmission of infection by gastrointestional endoscopy: May 2001

Abstract

IntroductionIn order to promote the appropriate use of new or emerging endoscopic techniques, the ASGE Technology Committee has developed a series of status evaluation papers. By this process relevant information about these technologies may be presented to practicing physicians for the education and care of their patients. In many cases, data from randomized control trials are lacking and only preliminary clinical trials are available. Practitioners should continue to monitor the medical literature for subsequent data about efficacy, safety, and socioeconomic aspects of the technologies.BackgroundFlexible gastrointestinal endoscopes are complex reusable instruments that require unique consideration with respect to cleaning and disinfection. In addition to the external surface, internal channels for air, water, and accessories are exposed to body fluids and other contaminants. In contrast to rigid endoscopes and some reusable accessories, flexible endoscopes are heat-labile and cannot be autoclaved. Professional organizations including the American Society for Gastrointestinal Endoscopy, the American College of Gastroenterology, the American Gastroenterological Association, the Society for Gastroenterology Nurses and Associates, the British Society of Gastroenterology, the Association for Professionals in Infection Control and Epidemiology, the American Society for Testing and Materials, and the Association of Operating Room Nurses have issued guidance documents for the reprocessing of gastrointestinal endoscopes.1Dimarino AJ Gage T Leung J Ravich W Wolf D Zuckerman G et al.Reprocessing of flexible gastrointestinal endoscopes.Gastrointest Endosc. 1996; 43: 540-546Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar, 2Society of Gastroenterology Nurses and Associates, Inc Standards of infection control in reprocessing of flexible gastrointestinal endoscopes.Gastroenterol Nursing. 2000; 23: 172-187Crossref PubMed Scopus (34) Google Scholar, 3Endoscopy Committee Working Party BSG Cleaning and disinfection of equipment for gastrointestinal flexible endoscopy: Interim recommendations of a working party of the British Society of Gastroenterology.Gut. 1988; 29: 1134-1151Crossref PubMed Scopus (153) Google Scholar, 4Alvarado CJ Reichelderfer M. APIC guidelines for infection prevention and control in flexible endoscopy.Am J Infect Control. 2000; 28: 138-155Abstract Full Text Full Text PDF PubMed Scopus (215) Google Scholar, 5American Society for Testing and Materials Standard practice for cleaning and disinfection of flexible fiberoptic and video endoscopes used in the examination of the hollow viscera. West Conshohocken, Pennsylvania2000Google Scholar These documents are intended to aid users of endoscopy equipment to achieve the accepted standard of high-level disinfection, defined as the destruction of all microorganisms with the exception of high levels of bacterial spores.6Rutala WA. APIC guideline for the selection and use of disinfectants.Am J Infect Control. 1996; 24: 313-342Abstract Full Text PDF PubMed Scopus (393) Google ScholarThe transmission of infectious organisms during gastrointestinal endoscopy is a concern both to the medical profession and the general public. However, such transmission is a rare event, with the frequency estimated to be 1 in 1.8 million cases.7Kimmey MB Burnett DA Carr-Locke DL DiMarino AJ Jensen DM Katon R et al.Transmission of infection by gastrointestinal endoscopy.Gastrointest Endosc. 1993; 36: 885-888Abstract Full Text PDF Scopus (82) Google Scholar When bacterial and viral transmissions have been reported, such instances have resulted from failure to adhere to currently established reprocessing guidelines.4Alvarado CJ Reichelderfer M. APIC guidelines for infection prevention and control in flexible endoscopy.Am J Infect Control. 2000; 28: 138-155Abstract Full Text Full Text PDF PubMed Scopus (215) Google ScholarTransmission of microorganismsA 1993 review article cited 281 cases of transmission of microorganisms by gastrointestinal endoscopy.8Spach DH Silverstein FE Stamm WE. Transmission of infection by gastrointestinal endoscopy and bronchoscopy.Ann Int Med. 1993; 118: 117-128Crossref PubMed Scopus (439) Google Scholar The majority of these cases predated the adoption of guidelines established in 1988, which stressed the importance of adequate manual cleaning before disinfection. Between 1988 and 1992, 28 cases of infections related to endoscopy were reported. It was estimated that approximately 40 million gastrointestinal endoscopies were done during that same period in the United States, resulting in an estimated transmission rate of infection by gastrointestinal endoscopy of 1 in 1.8 million.7Kimmey MB Burnett DA Carr-Locke DL DiMarino AJ Jensen DM Katon R et al.Transmission of infection by gastrointestinal endoscopy.Gastrointest Endosc. 1993; 36: 885-888Abstract Full Text PDF Scopus (82) Google Scholar This infection rate may be an underestimate due to factors such as incomplete surveillance, underreporting, asymptomatic infections, and infections with a long incubation period, but transmission of infection via gastrointestinal endoscopy appears to be rare.Various classes of infectious agents have different patterns of resistance to germicides, the recognition of which is important for developing strategies for endoscope and accessory reprocessing. The most resistant organisms are bacterial spores (Bacillus and Clostridium) followed by, in descending order, mycobacteria and nonlipid viruses (e.g., poliovirus, hepatitis A virus), vegetative fungi and bacteria, and finally lipid-containing viruses such as HBV and HIV that are highly sensitive to germicides. Hepatitis C virus (HCV) is also a lipid-containing virus and is likely to be similarly sensitive.9Bond WW. Overview of infection control problems: Principles in gastrointestinal endoscopy.Gastrointest Endosc Clin N Am. 2000; 10: 199-213PubMed Google Scholar Processes that eliminate high numbers of bacterial spores will likely eliminate all other microbial life as well.In addition to the type of microorganism, factors important in the transmission of infection during gastrointestinal endoscopy include the concentration of microorganism, efficacy and compliance with cleaning and disinfection procedures, and equipment design. Infections can be transmitted either patient-to-patient, health care worker-to-patient, or patient-to-health care worker.Episodes of transmission of infection to patients can be traced, in most cases, to procedural errors in cleaning and disinfection of the endoscope or its accessories. Bacteria or viruses have been transmitted by (1) inadequately cleaned endoscopes in which organisms may be concentrated in surface irregularities or other areas of limited accessibility, (2) contaminated water bottles and irrigating solutions, (3) improper use of or inadequately designed automated endoscope reprocessors, (4) use of substandard disinfectant solutions, and (5) inadequate drying of endoscope channels before storage.Viral transmissionMuch concern exists regarding the possible transmission of viruses at the time of endoscopy. There has been only one report of patient-to-patient hepatitis B virus transmission via flexible endoscopy. This occurred with a nonimmersible endoscope that is no longer recommended for use. Because the endoscope was not fully immersible, the air-water channel was not exposed to the disinfecting solution.10Birnie GG Quigley EM Clements GB Follett EA Watkinson G. Endoscopic transmission of hepatitis B virus.Gut. 1983; 24: 171-174Crossref PubMed Scopus (186) Google Scholar When current standards of endoscope design and reprocessing are applied, prospective studies of patients harboring hepatitis B have failed to demonstrate its transmission to subsequent patients during gastrointestinal endoscopy.8Spach DH Silverstein FE Stamm WE. Transmission of infection by gastrointestinal endoscopy and bronchoscopy.Ann Int Med. 1993; 118: 117-128Crossref PubMed Scopus (439) Google ScholarIsolated cases of patient-to-patient transmission of HCV related to colonoscopy were reported in 1997.11Bronowicki JP Vernard V Botté C Monhoven N Gastin I Choné L et al.Patient-to-patient transmission of hepatitis C virus during colonoscopy.N Engl J Med. 1997; 337: 237-240Crossref PubMed Scopus (401) Google Scholar A patient known to be infected with HCV underwent colonoscopy and biopsy; two subsequent patients had colonoscopy immediately after the index patient and were later shown to have contracted HCV of an identical genotype and nucleotide sequence. Transmission of viral infection in this case occurred because of (1) failure to brush the biopsy channel, (2) failure to ultrasonically clean and steam sterilize reusable biopsy forceps, (3) and an inadequate exposure to the liquid chemical germicide. Adherence to current reprocessing guidelines effectively eliminates the risk of HCV transmission from endoscopy.12Chanzy B Duc-Bin DL Rousset B Morand P Morel-Baccard C Marchetti B et al.Effectiveness of a manual disinfection procedure in eliminating hepatitis C virus from experimentally contaminated endoscopes.Gastrointest Endosc. 1999; 50: 147-151Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar, 13Deva AK Vickery J Zou J West RH Selby W Benn RAV et al.Detection of persistent vegetative bacteria and amplified viral nucleic acid from in-use testing of gastrointestinal endoscopes.J Hosp Infect. 1998; 39: 149-157Abstract Full Text PDF PubMed Scopus (59) Google ScholarHIV is readily destroyed by high-level disinfection. No documented cases of HIV transmission have occurred related to gastrointestinal endoscopy. It has been demonstrated that in endoscopes deliberately contaminated with HIV, the virus is eliminated in all cases by using standard manual cleaning and high-level disinfection protocols.14Hanson PJV Gor D Jeffries DJ Collins JV. Elimination of high titre HIV from fibreoptic endoscopes.Gut. 1990; 31: 657-659Crossref PubMed Scopus (78) Google Scholar The Center for Disease Control stated that currently recommended procedures for disinfection of endoscopes are adequate for instruments contaminated with HIV.15Centers for Disease Control Recommendations for prevention of HIV transmission in health care settings.MMWR. 1987; 36: 3S-18SPubMed Google ScholarBacterial transmissionTransmission of bacterial infections to patients is rarely encountered in current endoscopic practice. Organisms reported to have been be transmitted include gram-negative bacilli such as Salmonella spp,16O'Conner BH Bennet JR Alexander JF Sutton DR Leighton I Mawer SL et al.Salmonellosis infection transmitted by fiberoptic endoscopes.Lancet. 1982; 2: 864-866Abstract PubMed Scopus (46) Google Scholar, 17Dwyer DM Klein EG Istre GR Robinson MG Neumann DA McCoy GA. Salmonella newport infections transmitted by fiberoptic colonoscopy.Gastrointest Endosc. 1987; 33: 84-87Abstract Full Text PDF PubMed Scopus (87) Google Scholar Escherichia coli,18Parker HW Geenan JE Bjork JT Stewart ET A prospective analysis of fever and bacteremia following ERCP.Gastrointest Endosc. 1989; 25: 102-103Abstract Full Text PDF Scopus (46) Google Scholar Pseudomonas,19Cryan EM Falkiner FR Mulvihill TE Keane CT Keeling PW. Pseudomonas aeruginosa cross-infection following endoscopic retrograde cholangiopancreatography.J Hosp Infect. 1984; 5: 371-376Abstract Full Text PDF PubMed Scopus (49) Google Scholar, 20Struelens MJ Rost F Deplano A Maas A Schwam V Serruys E et al.Pseudomonas aeruginosa and Enterobacteriaceae bacteremia after biliary endoscopy: An outbreak investigation using DNA macrorestriction analysis.Am J Med. 1993; 95: 489-498Abstract Full Text PDF PubMed Scopus (137) Google Scholar Klebsiella,18Parker HW Geenan JE Bjork JT Stewart ET A prospective analysis of fever and bacteremia following ERCP.Gastrointest Endosc. 1989; 25: 102-103Abstract Full Text PDF Scopus (46) Google Scholar Enterobacter spp,20Struelens MJ Rost F Deplano A Maas A Schwam V Serruys E et al.Pseudomonas aeruginosa and Enterobacteriaceae bacteremia after biliary endoscopy: An outbreak investigation using DNA macrorestriction analysis.Am J Med. 1993; 95: 489-498Abstract Full Text PDF PubMed Scopus (137) Google Scholar Serratia marcescens,21Gorse GJ Messner RL. Infection control practices in gastrointestinal endoscopy in the United States: a national survey.Infect Control Hosp Epidemiol. 1991; 12: 289-296Crossref PubMed Scopus (87) Google Scholar and Helicobacter pylori.22Langenberg W Rauws EAJ Oudbier JH Tytgat GNJ. Patient-to-patient transmission of Campylobacter pylori infection by fiberoptic gastroduodenoscopy and biopsy.J Infect Dis. 1990; 161: 507-511Crossref PubMed Scopus (185) Google Scholar Infections occur as a consequence of inadequate endoscope reprocessing or because of contaminated water sources. A study published in 1999 reaffirmed that use of accepted reprocessing guidelines effectively eliminates bacteria and other microorganisms from endoscopes.23Cronmiller JR Nelson DK Salman G Jackson DK Dean RS Hsu JJ et al.Antimicrobial efficacy of endoscopic disinfection procedures: a controlled, multifactorial investigation.Gastrointest Endosc. 1999; 50: 152-158Abstract Full Text Full Text PDF PubMed Scopus (41) Google ScholarEndoscopic transmission of Salmonella has been reported in 84 patients.16O'Conner BH Bennet JR Alexander JF Sutton DR Leighton I Mawer SL et al.Salmonellosis infection transmitted by fiberoptic endoscopes.Lancet. 1982; 2: 864-866Abstract PubMed Scopus (46) Google Scholar, 17Dwyer DM Klein EG Istre GR Robinson MG Neumann DA McCoy GA. Salmonella newport infections transmitted by fiberoptic colonoscopy.Gastrointest Endosc. 1987; 33: 84-87Abstract Full Text PDF PubMed Scopus (87) Google Scholar, 24Holmberg SD Osterholm MT Senger KA Cohen ML. Drug-resistant Salmonella from animals fed antimicrobials.N Eng J Med. 1984; 311: 617-622Crossref PubMed Scopus (292) Google Scholar, 25Tuffnell PG. Salmonella infections transmitted by a gastroscope.Can J Public Health. 1976; 67: 141-142Google Scholar, 26Chmel H Armstrong D. Salmonella oslo: a focal outbreak in a hospital.Am J Med. 1976; 60: 203-208Abstract Full Text PDF PubMed Scopus (56) Google Scholar, 27Beecham HJ Cohen ML Parkin WE. Salmonella typhimurium: transmission by fiberoptic upper gastrointestinal endoscopy.JAMA. 1979; 241: 1013-1015Crossref PubMed Scopus (69) Google Scholar Suboptimal reprocessing was implicated in each case. There have been no reports of Salmonella infection when current guidelines for high-level disinfection have been followed.Forty-five cases of endoscopic transmission of Pseudomonas have been reported. Infection with this organism generally occurs as a consequence of contamination of the water source (either an inadequately disinfected water bottle feeding the endoscope or contamination of an automated reprocessing machine) as well as a breach in accepted cleaning, disinfection, and storage procedures.8Spach DH Silverstein FE Stamm WE. Transmission of infection by gastrointestinal endoscopy and bronchoscopy.Ann Int Med. 1993; 118: 117-128Crossref PubMed Scopus (439) Google Scholar, 28Doherty DE Falko JM Lefkovitz N Rogers J Fromkes J. Pseudomonas aeruginosa sepsis following endoscopic retrograde cholangiopancreatography (ERCP).Dig Dis Sci. 1982; 27: 169-170Crossref PubMed Scopus (53) Google Scholar, 29Earnshaw JJ Clark AW Thom BT. Outbreak of Pseudomonas aeruginosa following endoscopic retrograde cholangio-pancreatography.J Hospi Infect. 1985; 6: 95-97Abstract Full Text PDF PubMed Scopus (57) Google Scholar, 30Allen JI Allen MO Olson MM Gerding DN Shanholtzer CJ Meier PB et al.Pseudomonas infection of the biliary system resulting from use of a contaminated endoscope.Gastroenterology. 1987; 92: 759-763Abstract PubMed Google ScholarThere are isolated reports of transmission of other bacteria including Staphylococcus,18Parker HW Geenan JE Bjork JT Stewart ET A prospective analysis of fever and bacteremia following ERCP.Gastrointest Endosc. 1989; 25: 102-103Abstract Full Text PDF Scopus (46) Google Scholar Serratia,21Gorse GJ Messner RL. Infection control practices in gastrointestinal endoscopy in the United States: a national survey.Infect Control Hosp Epidemiol. 1991; 12: 289-296Crossref PubMed Scopus (87) Google Scholar Klebsiella,18Parker HW Geenan JE Bjork JT Stewart ET A prospective analysis of fever and bacteremia following ERCP.Gastrointest Endosc. 1989; 25: 102-103Abstract Full Text PDF Scopus (46) Google Scholar Enterobacter,31Elson CO Hattori K Blackstone MO. Polymicrobial sepsis following endoscopic retrograde cholangiopancreatography.Gastroenterology. 1979; 69: 507-510Google Scholar and Helicobacter pylori.22Langenberg W Rauws EAJ Oudbier JH Tytgat GNJ. Patient-to-patient transmission of Campylobacter pylori infection by fiberoptic gastroduodenoscopy and biopsy.J Infect Dis. 1990; 161: 507-511Crossref PubMed Scopus (185) Google Scholar, 32Wu MS Wang JT Yang JC Wang HH Sheu JC Chen DS et al.Effective reduction of Helicobacter pylori infection after upper gastrointestinal endoscopy by mechanical washing of the endoscope.Hepatogastroenterology. 1996; 43: 1660-1664PubMed Google Scholar However, in each instance manual cleaning, disinfection, or storage techniques were found to have been inadequate.Although bacterial spores are the most resistant to liquid chemical germicides, there have been no reported cases of endoscopic transmission of infections with these organisms.4Alvarado CJ Reichelderfer M. APIC guidelines for infection prevention and control in flexible endoscopy.Am J Infect Control. 2000; 28: 138-155Abstract Full Text Full Text PDF PubMed Scopus (215) Google Scholar Studies have shown that C difficile spores can be completely inactivated by standard reprocessing techniques.33Rutala WA Gergen MF Weber DJ. Inactivation of Clostridium difficile spores by disinfectants.Infection Control Hosp Epidemiol. 1993; 14: 36-39Crossref PubMed Scopus (75) Google ScholarAlthough easier to eradicate than bacterial spores, mycobacteria are also difficult to eliminate with chemical sterilants or disinfectants. Although cases of mycobacterial transmission have been documented during bronchoscopy,34Michele TM Cronin WA Graham N et al.Transmission of Mycobacterium tuberculosis by a fiberoptic brochoscope.JAMA. 1997; 278: 1093-1096Crossref PubMed Google Scholar, 35Agerton T Valway S Gore B Pozsik C Plikaytis B Woodley C et al.Transmission of a highly drug-resistant strain (Strain W1) of Mycobacterium tuberculosis.JAMA. 1997; 278: 1073-1077Crossref PubMed Google Scholar there are no reported cases of transmission by gastrointestinal endoscopy. Gluteraldehyde, hydrogen peroxide, and peracetic acid, used appropriately in association with mechanical cleaning, have all been demonstrated to adequately eradicate mycobacteria, both Mycobacterium tuberculosis and the atypical mycobacteria.36Walter VA DiMarino AJ. American Society for Gastrointestinal Endoscopy-Society of Gastroenterology Nurses and Associates endoscope reprocessing guidelines.Gastrointest Endosc Clin N Am. 2000; 10: 265-273PubMed Google Scholar, 37Muscarella LF. Automatic flexible endoscope reprocessors.Gastrointest Endosc Clin N Am. 2000; 10: 245-257PubMed Google ScholarMiscellaneous microbial transmissionThere have been 4 cases of Strongyloides esophagitis reported from a single contaminated endoscope.38Mandelstam P Sugawa C Silvis SE Nebel OT Rogers BHG. Complications associated with esophagogastroduodenoscopy and with esophageal dilation.Gastrointest Endosc. 1976; 23: 16-19Abstract Full Text PDF PubMed Scopus (178) Google Scholar There have been no reported cases of transmission of fungi resulting from gastrointestinal endoscopy.Concern has been raised over possible endoscopic transmission of prions and other transmissible spongiform encephalopathies (TSE), including Creutzfeldt-Jakob disease, kuru, and bovine spongiform encephalopathy. There have been no reported cases of transmission of these agents by endoscopy. The World Health Organization recommends that the decontamination of medical instruments should be guided by the infectivity level of the tissue contaminating the instrument. Saliva, gingival tissue, intestinal tissue, feces, and blood are classified as having no detectable infectivity and, for the purposes of infection control for these agents, are regarded as noninfectious.39World Health Organization. WHO infection control guidelines for transmissible spongiform encephalopathies. WHO Infection Control Guidelines for Transmissible Spongiform. Report of a WHO Consultation, Geneva, Switzerland, 23-26 March 1999. Publication WHO/CDS/CSR/APH/2000.3. Geneva, Switzerland. http://www.who.int/emc-documents/tse/whocdscsraph 2003c.html.Google Scholar A draft statement on TSE and endoscopes from the Centers for Disease Control (CDC) concluded that current guidelines for cleaning and disinfection of the instruments need not be changed.4Alvarado CJ Reichelderfer M. APIC guidelines for infection prevention and control in flexible endoscopy.Am J Infect Control. 2000; 28: 138-155Abstract Full Text Full Text PDF PubMed Scopus (215) Google Scholar, 40Rutala WA Weber DJ. Creutzfeld-Jakob disease: recommendations for disinfection and sterilization.Clin Inf Dis. 2001; 32: 1348-1356Crossref PubMed Scopus (171) Google ScholarRisks to or from health-care workersTransmission of infection from a health care worker to a patient at the time of gastrointestinal endoscopy has not been reported. In contrast, transmission of infection from patient to staff is suggested by the higher prevalence of H pylori infection among gastroenterologists compared with other physicians.41Lin SK Lambert JR Schembri MA Nicholson L Korman MG. Helicobacter pylori prevalence in endoscopy and medical staff.J Gastroenterol Hepatol. 1994; 9: 319-324Crossref PubMed Scopus (72) Google Scholar Additional concerns include body fluid exposures from needle stick injuries (hypodermic needles and other sharp objects (such as spiked biopsy forceps) and splash injuries.42Mohandas KM Gopalakrishnan G. Mucocutaneous exposure to body fluids during digestive endoscopy: the need for universal precautions.Indian J Gastroenterol. 1999; 18: 109-111PubMed Google Scholar CDC guidelines state that all patients be treated as potential carriers of blood-borne pathogens; universal precautions should be followed at all times in the care of patients.43Centers for Disease Control Perspectives in disease prevention and health promotion update: universal precautions for prevention of transmission of human immunodeficiency virus, hepatitis B virus, and other bloodborne pathogens in health-care settings.MMWR. 1988; 37: 377-388PubMed Google ScholarEndoscope design issuesFlexible gastrointestinal endoscopes are complex instruments. They have channels and ports that may acquire surface breaks and irregularities with use over time, as well as movable parts (such as the elevator on a duodenoscope) where organic debris and possibly microorganisms may become lodged. These areas may be relatively inaccessible to contact with liquid chemical germicides. Because endoscopes are heat-sensitive instruments and cannot be autoclaved, sterilization cannot be guaranteed. Thus, although the available evidence suggests that the rate of transmission of infection via gastrointestinal endoscopy is extremely low, potential risk exists. Manufacturers have been encouraged to redesign endoscopes to facilitate the cleaning and disinfection process. Quality control and assessment of the adequacy of high-level disinfection is particularly important if clinical or epidemiologic findings suggest an endoscopy-related transmission of infection.44Merighi A Contato E Scagliarini R Mirolo G Tampieri ML Pazzi P et al.Quality improvement in gastrointestinal endoscopy: microbiologic surveillance of disinfection.Gastrointest Endosc. 1996; 43: 457-462Abstract Full Text Full Text PDF PubMed Scopus (31) Google ScholarEndoscope reprocessingThe importance of strict adherence to reprocessing guidelines cannot be overemphasized.1Dimarino AJ Gage T Leung J Ravich W Wolf D Zuckerman G et al.Reprocessing of flexible gastrointestinal endoscopes.Gastrointest Endosc. 1996; 43: 540-546Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar, 2Society of Gastroenterology Nurses and Associates, Inc Standards of infection control in reprocessing of flexible gastrointestinal endoscopes.Gastroenterol Nursing. 2000; 23: 172-187Crossref PubMed Scopus (34) Google Scholar, 3Endoscopy Committee Working Party BSG Cleaning and disinfection of equipment for gastrointestinal flexible endoscopy: Interim recommendations of a working party of the British Society of Gastroenterology.Gut. 1988; 29: 1134-1151Crossref PubMed Scopus (153) Google Scholar, 4Alvarado CJ Reichelderfer M. APIC guidelines for infection prevention and control in flexible endoscopy.Am J Infect Control. 2000; 28: 138-155Abstract Full Text Full Text PDF PubMed Scopus (215) Google Scholar, 5American Society for Testing and Materials Standard practice for cleaning and disinfection of flexible fiberoptic and video endoscopes used in the examination of the hollow viscera. West Conshohocken, Pennsylvania2000Google Scholar, 45American Society for Gastrointestinal Endoscopy Infection control during gastrointestinal endoscopy.Gastriointest Endosc. 1999; 49: 836-841Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar Components of a successful program for reprocessing GI endoscopes must include all of the following: (1) mechanical cleaning and rinsing of all exposed internal and external surfaces; (2) use of an effective liquid chemical germicide (LCG) at an for recommended duration and at recommended temperature (which includes monitoring the LCG's minimum effective concentration [MEC]); (3) further rinsing; and (4) proper drying and storage technique.45American Society for Gastrointestinal Endoscopy Infection control during gastrointestinal endoscopy.Gastriointest Endosc. 1999; 49: 836-841Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar, 46Gerding DN Peterson LR Vennes JA. Cleaning and disinfection of fiberoptic endoscopes: evaluation of glutaraldehyde exposure time and forced air drying.Gastroenterology. 1982; 83: 613-618Abstract Full Text PDF PubMed Scopus (53) Google Scholar Appropriate training in these techniques, as well as strict compliance with policies based on published guidelines, are required.Mechanical cleaningMechanical cleaning is a vital step in endoscope reprocessing and has been shown to remove over 99.9% of microbes from the endoscope (a 3- to 4-log10 reduction).23Cronmiller JR Nelson DK Salman G Jackson DK Dean RS Hsu JJ et al.Antimicrobial efficacy of endoscopic disinfection procedures: a controlled, multifactorial investigation.Gastrointest Endosc. 1999; 50: 152-158Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar, 37Muscarella LF. Automatic flexible endoscope reprocessors.Gastrointest Endosc Clin N Am. 2000; 10: 245-257PubMed Google Scholar, 47Urayama S Kozarek R Sumida S Raltz S Merriam L Pethigal P. Mycobacteria and gluteraldehyde: is high level disinfection of endoscopes possible?.Gastrointest Endosc. 1996; 43: 451-456Abstract Full Text Full Text PDF PubMed Google Scholar, 48Kovacs BJ Chen YK Kettering JD Aprecio RM Roy I. High-level disinfection of gastrointestinal endoscopes: are current guidelines adequate?.Am J Gastroenterol. 1999; 94: 1546-1550Crossref PubMed Scopus (34) Google Scholar After use, an endoscope retains organic materials such as blood, mucus, and saliva, which may be rich in microorganisms. If this debris is allowed to remain, ineffective contact and penetration of the disinfectant may result. Immediately after completion of an endoscopic procedure, a low-sudsing detergent solution should be suctioned through the channels. After transferring the endoscope to the reprocessing area, the suction, air/water valves, and biopsy port cap should be removed. The endoscope, valves, and cap should then be submerged in a fresh detergent solution. Manual cleaning with cloths, sponges, and soft wire brushes of various sizes should be utilized to mechanically dislodge debris. The detergent solution should then be suctioned and flushed through the endoscope channels. Automated reprocessors used for disinfection of endoscopes do not replace the need for manual cleaning.37Muscarella LF. Automatic flexible endoscope reprocessors.Gastrointest Endosc Clin N Am. 2000; 10: 245-257PubMed Google Scholar, 49Nelson DB Bosco JJ Curtis WD Faigel DO Kelsey PB Laing K et al.Automatic endoscope reprocessors.Gastrointest Endosc. 1999; 50: 925-927Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar Endoscopic accessories that penetrate the gastrointestinal mucosa should be mechanically cleaned and sterilized after each use. Those that are heat stable should be heat sterilized.50Rutala WA Clontz EP Weber DJ Hoffmann KK. Disinfection practices for endoscopes and other semicritical items.Infect Control Hosp Epidemiol. 1991; 12: 282-288Crossref PubMed Scopus (85) Google Scholar, 51American Society for Testing and Materials Standard practice for reprocessing of reusable, heat-stable endoscopic accessory instruments (EAI) used with flexible endoscopes. West Conshohocken, Pennsylvania1999Google ScholarChemical disinfectionAfter thorough manual cleaning has been performed, the next step is high-level chemical disinfection. High-level disinfection is a process that results in the destruction of all vegetative bacteria, viruses, fungi, and mycobacteria but not necessarily all bacterial spores. The Food and Drug Administration (FDA) has approved 5 chemicals for use as high-level disinfectants or sterilants in the reprocessing of endoscopes (reusable medical devices): glutaraldehy