Gaining perspective on reprocessing of GI endoscopes

Abstract

Attention to the cleaning and reprocessing of flexible endoscopes has increased considerably since the advent of GI endoscopy nearly four decades ago. The subject encompasses important issues regarding both infection control and cost containment. Recent seemingly orchestrated discussions in the lay media have further heightened interest in, and anxiety about, the topic. Two articles in this issue1Chanzy 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 Scopus (52) Google Scholar, 2Cronmiller JR Nelson DK Salman G Jackson D 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 Scopus (41) Google Scholar and another from the May 1999 issue of Gastrointestinal Endoscopy 3Barbee SL Weber DJ Sobsey MD Rutala WA Inactivation of Cryptosporidium parvum oocyst infectivity by disinfection and sterilization processes.Gastrointest Endosc. 1999; 49: 605-611Google Scholar address focused questions within the reprocessing debate. To put their findings in perspective it is helpful to understand the background and evolution of endoscope reprocessing. During the early years of flexible endoscopy, minimal washing of the instrument surface and flushing of the suction/accessory channel were performed. This approach is still used in some underserved areas of the world today. In the 1970s brief flushing of disinfectant through the internal suction/accessory channel was inconsistently adopted. In the late 1970s and early 1980s post-ERCP bacteremias from water-borne Pseudomonas species were well documented and attributed to inadequate drying of channels prior to overnight storage. This stimulated more widespread use of alcohol flushes to aid in drying of internal channels, end-of-day forced air drying, and upright storage to facilitate runoff of retained droplets. During this interval automated reprocessors were developed to reduce exposure of personnel to toxic disinfectants and to provide consistent disinfection of internal channels, which had previously been neglected. Before 1983, instruments were not submersible for cleaning or disinfection; the suction channel in the universal cord could not be brushed; and the elevator, air, and water channels were generally not accessible, or were not flushed, for cleaning or disinfection. Instruments used on potentially infectious patients were sent for ethylene oxide (EtO) gas sterilization. Most endoscopy units had instruments designated for use on high-risk patients. With the recognition of the need for universal precautions against the potential risk of human immmunodeficiency virus (HIV) and hepatitis B virus, formal and informal standards for reprocessing began to emerge in the mid to late 1980s. Most emphasized the importance of adequate manual cleaning followed by 5- or 10-minute contact with glutaraldehyde or other disinfectants, now termed liquid chemical germicides (LCGs).4American Society of Gastrointestinal Endoscopy Infection control during gastrointestinal endoscopy: guidelines for clinical application.Gastrointest Endosc. 1988; 34: 37S-40SGoogle Scholar, 5British Society of Gastroenterology Cleaning and disinfection of equipment—gastrointestinal flexible endoscopy: interim recommendation of a Working Party of the British Society of Gastroenterology.Gut. 1988; 29: 1134-1151Google Scholar In the early 1990s controversy arose regarding immersion times for high-level disinfection using 2% glutaraldehyde. Before 1993 disinfectants and sterilants for hospital use were regulated under the Environmental Protection Agency (EPA) oversight of pesticides. In 1993 the EPA and the Food and Drug Administration (FDA) divided their oversight responsibilities. Since then the EPA has had jurisdiction over disinfectants used for cleaning of the hospital environment and of noncritical items and the FDA has had jurisdiction over sterilants used for reprocessing of “critical” and “semi-critical” medical devices.6Rutala WA Weber DJ FDA labeling requirements for disinfection of endoscopes: a counterpoint.Infect Control Hosp Epidemiol. 1995; 16: 231-235Google Scholar Liquid sterilants are themselves classified as devices by the FDA, and, as such, they require written clearance for marketing under section 510[k] of the FD&C Act. The first such 510[k] approval for a glutaraldehyde solution was sought by Johnson and Johnson Medical, Inc., for its product Cidex. At that time the FDA required labeling and package inserts incorporating the explicit details of long-standing Cidex documentation for high-level disinfection (e.g., 2.4% glutaraldehyde soak for 45 minutes at 25° C (77° F) to yield 100% kill of Mycobacterium tuberculosis ). Such labeling is based on tests for tuberculocidal activity that do not allow for prior manual cleaning. Rather, they are conducted in the presence of a heavy protein load (horse serum) and they use an extremely high number of organisms. Manual cleaning was not incorporated in such labeling requirements because it cannot be controlled by the manufacturer or the FDA. This does not imply that use of a prolonged contact time without manual cleaning is acceptable. Concurrent with these labeling changes, several reports described inconsistent or inadequate reprocessing of endoscopes in a significant proportion of surveyed units.7Kaczmarek RG Moore RM McCrohan J Goldmann DA Reynolds C Caquelin C et al.Multi-state investigation of the actual disinfection/sterilization of endoscopes in health care facilities.Am J Med. 1992; 92: 257-261Google Scholar, 8Favero MS Strategies for disinfection and sterilization of endoscopes: the gap between basic principles and actual practice.Infect Control Hosp Epidemiol. 1991; 12: 279-281Google Scholar These combined concerns led to a multispecialty position statement by the American Society for Gastrointestinal Endoscopy, American College of Gastroenterology, American Gastroenterological Association, and the Society for Gastrointestinal Nurses and Associates in 1995 that stressed the importance of mechanical cleaning as the first step in reprocessing.9American Society for Gastrointestinal Endoscopy Reprocessing of flexible gastrointestinal endoscopes.Gastrointest Endosc. 1996; 43: 540-546Google Scholar Emphasis was also placed on the responsibility for individual endoscopy units to develop written protocols and training and quality assurance programs for endoscope reprocessing. This joint position paper promulgated 20-minute contact times for glutaraldehyde on the basis of relatively scant nonclinical data, in contrast to both the widespread use of 10 minutes and the new 45-minute labeling instructions. Not all societies of gastroenterology have followed suit, however. The European Society of Gastroenterology recommends contact with “2% glutaraldehyde or other chemical disinfectant of equal potency” for “not less than 10 minutes.”10Axon A Kruse A Urgell R Struelens M Petersen C Spencer K Rey JF European Society of Gastro-Intestinal Endoscopy: guidelines on cleaning and disinfection in gastrointestinal endoscopy.Endoscopy. 1995; 27: 199-202Google Scholar, 11http://www.esge.com/guidereprocessing.htmlGoogle Scholar Given these changes and the persisting differences among recommendations, one might ask against what standard are the guidelines being measured? Our current standards evolved from the Spaulding classification of medical device reprocessing. Over the last three decades, these principles have provided a rational and practical approach to disinfection for all medical devices.12Rutala WA APIC guideline for selection and use of disinfectants.Am J Infect Control. 1996; 24: 313-342Google Scholar Devices are categorized on the basis of the relative risk of infection associated with their use: critical devices are those that enter sterile tissue or vasculature, semi-critical devices touch intact mucous membranes, and non-critical devices touch only intact skin. Reprocessing protocols are categorized by their anticipated microbial clearance. Sterilization is an absolute term that refers to the complete elimination of all forms of microbial life, including spore forms; high-level disinfection destroys all microorganisms except for some spores when found in high concentration; intermediate level disinfection inactivates vegetative bacteria, most viruses, most fungi, and mycobacterium tuberculosis, but not necessarily bacterial spores; low-level disinfection kills most bacteria, some fungi, and some viruses, but not resistant microorganisms or spores. Sterilization is advised for all critical devices, including endoscopes used within the peritoneal cavity, and all endoscopic accessories. High-level disinfection is advised for semi-critical devices, including flexible endoscopes used within the GI tract. High-level disinfection of flexible endoscopes requires 4 steps: (1) cleaning and rinsing, (2) disinfection, (3) further rinsing with filtered or sterile water, and (4) forced air drying and preparation for storage. Cleaning is the removal of all organic soil or foreign material from an object, usually via mechanical friction and washing with water and enzymes or detergents. On average, cleaning alone provides a 4 log, or 99.99%, reduction in microbial contaminants.12Rutala WA APIC guideline for selection and use of disinfectants.Am J Infect Control. 1996; 24: 313-342Google Scholar, 13Vesley D Norlien KG Nelson B Ott B Streifel AJ Significant factors in the disinfection and sterilization of flexible endoscopes.Am J Infect Control. 1992; 20: 291-300Google Scholar In the absence of careful physical cleaning, most disinfection and sterilization processes are likely to be ineffective. Among the widely available sterilization methods only steam heat autoclaving can overcome the barrier effects of residual organic matter.14Muscarella LF Are all sterilization processes alike?.AORN Journal. 1998; 67: 966-976Google Scholar Rinsing removes residual detergent solution prior to disinfection and remaining LCG before endoscope reuse. When not adequately rinsed, residual germicides can cause mucositis in patients. Because organisms found in tap water have been implicated in many bacteremias attributed to reprocessing, rinsing should be performed with small pore filtered or sterile water. High-level disinfection is most often performed in automated reprocessing machines using any of several LCGs. Manual cleaning is the only step that cannot be automated and thereby made error free. The disinfection steps can also be performed manually; however, this increases the potential for human error. Careful attention must be paid to adequate flushing of all internal channels of both the insertion tube and the umbilical cord. Two percent glutaraldehyde is the most commonly used reprocessing agent. Glutaraldehyde can be reused many times, making it very cost-effective on a per procedure basis. Its useful lifespan is influenced by additives and dilution with serial reuse. Use and disposal of glutaraldehyde require measures to prevent exposure of employees to toxic fumes and are subject to regulations of the Occupational Safety and Health Administration (OSHA) and the EPA. Alternative LCGs for endoscope reprocessing include oxidizing chemicals such as hydrogen peroxide and peracetic acid. Hydrogen peroxide solutions, like glutaraldehyde, can be reused in commonly available machines. Peracetic acid is consumed with each reprocessing cycle, yielding relatively innocuous by-products. Because it is not reusable, reprocessing costs tend to be higher. Only a single line of automated reprocessors are available for use of peracetic acid (Steris Process). The only widely available processes that provide terminal point-of-use sterility for critical-use devices are steam autoclaving and EtO gas treatment.14Muscarella LF Are all sterilization processes alike?.AORN Journal. 1998; 67: 966-976Google Scholar Autoclaving destroys flexible endoscopes and EtO sterilization requires 24 hours or more for instrument turnaround, an unacceptable burden to the economics and efficiency of more routine endoscopic applications. Sterilization of exposed and accessible surfaces can be accomplished with LCGs. The parameters of concentration, temperature, and contact time vary greatly among the available agents. Sterilization has not been recommended for semi-critical use of endoscopes within the GI tract, however, because (1) for current instruments, there are no independent data to demonstrate that it is possible to reliably and consistently achieve and monitor sterilization of the internal channels,15Muscarella LF High-level disinfection or “sterilization” of endoscopes?.Infect Control Hosp Epidemiol. 1996; 17: 183-187Google Scholar (2) there are no data demonstrating improved outcome, reduced infection rates, or improved safety with sterilization versus high-level disinfection, (3) there have been no demonstrable benefits to the further reduction in spore counts (e.g., Clostridium difficile ) achieved by gas treatment over high-level disinfection, and (4) there are no biologic indicators for sterility that can be adapted to instrument channel design, particularly for liquid chemical sterilants. These challenges prompt several legitimate questions. (1) Are the currently advised reprocessing regimens adequate when practiced appropriately, e.g., are they efficacious? Do they eradicate the pertinent organisms? If so, are they time efficient and cost-effective? (2) Are the same regimens adequate in practice, e.g., are they effective? Or can they be? (3) Is sterilization feasible or necessary—either in idealized settings or in practice? The articles for discussion attempt to answer specific aspects of these three questions. Subsequent to specific case reports16Bronowicki JP Venard V Botte C Monhoven N Gastin I Chone L et al.Patient-to-patient transmission of hepatitis C virus during colonoscopy.N Engl J Med. 1997; 337: 237-240Google Scholar and epidemiologic evidence17Andrieu J Barny S Colardelle P Maisonneuse P Giraud V Robin E et al.Prevalence et facteurs de risque de l’infection par le virus de l’hepatite C dans une population hospitalisee en gastroenterologie: role des biopsies per-endoscopiques.Gastroenterol Clin Biol. 1995; 19: 340-345Google Scholar for endoscopic transmission of hepatitis C, Chanzy et al.1Chanzy 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 Scopus (52) Google Scholar report on the effectiveness of a manual disinfection procedure for the elimination of hepatitis C virus from endoscopes. Following experimental contamination with 106Rutala WA Weber DJ FDA labeling requirements for disinfection of endoscopes: a counterpoint.Infect Control Hosp Epidemiol. 1995; 16: 231-235Google Scholar hepatitis C virus RNA, no copies of viral RNA were detected by polymerase chain reaction analysis after disinfection with a 4-step process involving (1) manual cleaning with enzymatic detergent plus a 15-minute detergent soak, (2) tap water rinse, (3) 20-minute manual disinfection in 2% glutaraldehyde solution, and (4) sterile water rinse. Although positive polymerase chain reaction results do not equate with infectivity, negative results demonstrating clearance of genetic material are reassuring. These data are in line with those of several other series demonstrating relatively efficient removal of hepatitis C virus, hepatitis B virus, and HIV with standard reprocessing regimens.18Rey JF Halfon P Feryn JM Khiri H Masseyeff MF Ouzan D Risque de transmission du virus de l’hepatite C par l’endoscopie digestive.Gastroenterol Clin Biol. 1995; 19: 346-349Google Scholar, 19Bond W Favero M Petersen N Ebert J Inactivation of hepatitis B virus by intermediate to high level disinfectant chemicals.J Clin Microbiol. 1983; 18: 535-538Google Scholar, 20Hanson PJV For D Jeffries KJ Collins JV Elimination of high titre HIV from fibreoptic endoscopes.Gut. 1990; 31: 657-659Google Scholar The few documented cases of hepatitis transmission in the literature are thought to represent lapses in the application of standard regimens.16Bronowicki JP Venard V Botte C Monhoven N Gastin I Chone L et al.Patient-to-patient transmission of hepatitis C virus during colonoscopy.N Engl J Med. 1997; 337: 237-240Google Scholar, 21Kimmey MB Burnett DA Carr-Locke DL DiMarino AJ Jensen DM Katon R et al.Transmission of infection by gastrointestinal endoscopy: ASGE Technology Assessment Committee position paper.Gastrointest Endosc. 1993; 39: 885-888Google Scholar The epidemiologic evidence, therefore, more likely represents failure in the application of accepted regimens than of the intended regimens themselves. Cronmiller et al.2Cronmiller JR Nelson DK Salman G Jackson D 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 Scopus (41) Google Scholar provide a useful controlled evaluation of several of the many variables present in the course of endoscope reprocessing, including manual washing or not; 10-, 20-, or 45-minute manual glutaraldehyde treatment versus automated peracetic acid treatment; and alcohol versus water rinse before drying. Following experimental inoculation of colonoscopes with 108Favero MS Strategies for disinfection and sterilization of endoscopes: the gap between basic principles and actual practice.Infect Control Hosp Epidemiol. 1991; 12: 279-281Google Scholar colony-forming units of Enterococci species, they demonstrated an average 3 log10 reduction in retrievable organisms (107 → 104) from manual cleaning alone. This is consistent with several other studies that have demonstrated 3 to 5 log10 reductions by washing alone.12Rutala WA APIC guideline for selection and use of disinfectants.Am J Infect Control. 1996; 24: 313-342Google Scholar, 13Vesley D Norlien KG Nelson B Ott B Streifel AJ Significant factors in the disinfection and sterilization of flexible endoscopes.Am J Infect Control. 1992; 20: 291-300Google Scholar Second, following cleaning, automated flushing with water alone in the automated reprocessor yielded a 2 log10 reduction in microbial load. Similar reductions can likely be anticipated from any automated flushing cycle, independent of the intended LCG. Third, using a sample plating technique for detection of organisms rather than a more sensitive broth culture technique, they demonstrated complete clearance of organisms with both the automated peracetic acid regimen and those manual glutaraldehyde regimens that incorporated 20 or 45 minutes of contact time and alcohol drying. Although encouraging in their demonstration of complete efficacy for currently advised regimens, the numbers are too small to accept as demonstrating differences against the nonstandard regimens practiced abroad (washing plus 10-minute contact time or air drying without alcohol). When using manual precleaning, their proportions of positive cycles are not likely to be statistically different between regimens using alcohol (1 of 15) versus air drying (2 of 15), those using 10-minute contact times (1 of 10) versus 20- to 45-minute contact times (2 of 20), or even between those combining alcohol and longer times (0 of 10) versus those not (3 of 20) (p = 0.53 by Fisher exact test). The cost analysis provided by Cronmiller et al.2Cronmiller JR Nelson DK Salman G Jackson D 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 Scopus (41) Google Scholar is lacking in detail and cannot be interpreted as analogous to other practice settings. The cost of $9.15 for precleaning is excessive, but it is not subdivided into personnel, supplies, and equipment costs to allow clarification. Similarly, in units where automated reprocessing allows efficient reuse of glutaraldehyde for a large volume of procedures, the per cycle cost is likely lower than demonstrated here. This study, funded by Steris, Inc., markedly understates the relative cost difference between glutaraldehyde and peracetic acid reprocessing. The implication that the automated peracetic acid–based “liquid sterilization system” suffices by itself, irrespective of precleaning, is a dangerous one. This study did not use organic fluids or debris to further challenge the cleaning and reprocessing regimens. Without adequate cleaning, residual serum, blood, and stool protect organisms from the LCG. In the setting of inadequate precleaning, reprocessing has been shown to fail whether using EtO gas,22Parker HH Johnson RB Effectiveness of ethylene oxide for sterilization of dental handpieces.J Dent. 1995; 23: 113-115Google Scholar peracetic acid23Deva AK Vickery K Zou J et al.Detection of persistent vegetative bacteria and amplified viral nucleic acid from in-use testing of gastrointestinal endoscopes.J Hosp Infect. 1998; 39: 149-157Google Scholar, 24Bradley CR Babb JR Ayliffe GAJ Evaluation of the Steris System 1 peracetic acid endoscope processor.J Hosp Infect. 1995; 29: 1143-1151Google Scholar or glutaraldehyde products.23Deva AK Vickery K Zou J et al.Detection of persistent vegetative bacteria and amplified viral nucleic acid from in-use testing of gastrointestinal endoscopes.J Hosp Infect. 1998; 39: 149-157Google Scholar Indeed, the complexity of endoscope design does challenge adequate cleaning and the reprocessing outcome. The same issue applies, however, to all reprocessing methods except steam autoclaving. The recent report by Barbee et al.3Barbee SL Weber DJ Sobsey MD Rutala WA Inactivation of Cryptosporidium parvum oocyst infectivity by disinfection and sterilization processes.Gastrointest Endosc. 1999; 49: 605-611Google Scholar regarding inactivation of Cryptosporidium parvum oocyst infectivity during reprocessing was the most unsettling among the articles. Cryptosporidium causes selflimited gastroenteritis in healthy people but may cause severe disease in immunocompromised patients. Cryptosporidiosis is transmitted via person-to-person and fecal-oral routes, it is resistant to chlorine levels commonly used in water supplies and public swimming pools, and the minimal infectious dose is rather small.25Casemore DP Epidemiological aspects of human cryptosporidiosis.Epidemiol Infect. 1990; 104: 1-28Google Scholar These factors contribute to its presence in up to 1% of asymptomatic persons, 2% to 6% of immunocompetent patients with diarrhea, and 14% to 24% of HIV-infected patients with diarrhea.26Guerrant RL Cryptosporidiosis: an emerging, highly infectious threat.Emerg Infect Dis. 1997; 3: 51-57Google Scholar Barbee et al.3Barbee SL Weber DJ Sobsey MD Rutala WA Inactivation of Cryptosporidium parvum oocyst infectivity by disinfection and sterilization processes.Gastrointest Endosc. 1999; 49: 605-611Google Scholar studied C parvum oocyst inactivation using seven common LCGs and environmental disinfectants or antiseptics. Infectivity was assessed via a cell culture assay. Sterilization was accomplished using a steam autoclave, EtO gas, or a hydrogen peroxide plasma sterilizer (Sterrad 100). The latter two processes were equally efficacious in an experimental setting mimicking the internal channels of an endoscope. Both processes have major logistical shortcomings, however. As mentioned, EtO requires significant downtime for gas evacuation and the plasma sterilizer requires that instruments be absolutely dry before reprocessing. Antiseptics and LCGs that did not reduce the infectivity of pellets containing 105 to 106 oocysts included a quaternary ammonium product, povidone-iodine, alcohol, and room temperature peracetic acid. A diminution in infectivity of less than 1 log was noted after treatment with glutaraldehyde (Cidex), Clorox, and Vesphene IIse. Heated peracetic acid (50°C, 12 minutes) and 3% hydrogen peroxide reduced infectivity by greater than 1 log10 . Only 6% hydrogen peroxide reduced infectivity by more than 3 log10 (the limits of detection for the assay). This effect was both time and concentration dependent, with maximal reduction evident when using a 6% solution for 20 minutes. Equally important is the demonstration by Barbee et al.3Barbee SL Weber DJ Sobsey MD Rutala WA Inactivation of Cryptosporidium parvum oocyst infectivity by disinfection and sterilization processes.Gastrointest Endosc. 1999; 49: 605-611Google Scholar of markedly diminishing oocyst infectivity with air drying. At 45% relative humidity, infectivity decreased by 2.9 log10 at 30 minutes, 3.8 log10 at 60 minutes, and greater than 4.0 log10 at 90 minutes. When considering the likely contaminating titers and the effects of manual cleaning, flushing, and drying, they concluded that endoscopes do not represent an important source for C parvum transmission and that the data “does not warrant any change in the current recommendations for the cleaning and disinfection of endoscopes.” Despite their reassurances, the uncertainties raised by these results should prompt further investigation of C parvum in clinical settings, and the described differences among currently available germicides should be evaluated in the context of full reprocessing regimens. In addition, they should prompt all endoscopy units to redouble their efforts to maintain consistently high-quality cleaning day-to-day and every day, and that between-procedure drying, as opposed to end-of-the-day drying, may be important for eradication of some organisms. How might we answer the previously posed questions at this point in time? (1) With rare exceptions, the experimental literature describes very high efficacy for currently advised endoscope reprocessing regimens. The two current reports that directly evaluated reprocessing regimens support that fact.1Chanzy 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 Scopus (52) Google Scholar, 2Cronmiller JR Nelson DK Salman G Jackson D 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 Scopus (41) Google Scholar (2) The effectiveness of currently available reprocessing regimens, in practice, has not been evaluated in a comprehensive prospective fashion. One might question their effectiveness by observing that elaborate or exacting processes are hard to maintain and by citing the epidemiologic data for hepatitis C, the surveys of reprocessing practices in the early 1990s, and the fact that virtually all reported cases of endoscopic transmission of infection have been attributed to breaches in recommended regimens.21Kimmey MB Burnett DA Carr-Locke DL DiMarino AJ Jensen DM Katon R et al.Transmission of infection by gastrointestinal endoscopy: ASGE Technology Assessment Committee position paper.Gastrointest Endosc. 1993; 39: 885-888Google Scholar On the other hand, the incidence of clinically important infection is clearly very low. Surveys have estimated infection rates of 1 in 1.8 million procedures.27Spach DH Silverstein FE Stamm WE Transmission of infection by gastrointestinal endoscopy and bronchoscopy.Ann Intern Med. 1993; 118: 117-128Google Scholar Although this undoubtedly understates their frequency, the lack of clinically evident problems in general practice and the lack of reports describing widespread outbreaks of hepatitis, HIV, or any other infection suggest that the current reprocessing regimens work. In addition, epidemiologic studies and surveys have not evaluated recent practices or outcomes subsequent to widespread adoption of the guidelines released only in 1995. To infer inadequacy of present recommendations from data regarding past practices and to imply, without data as some have done in the lay press, that alternative methods are inherently more safe, inappropriately intensifies the public’s anxieties and feeds the media hype. (3) No data exist regarding benefits of endoscope sterilization for routine GI applications. Moreover, many experts and engineers acknowledge that the very design of current endoscopes precludes effective sterilization.28Bond WW Ott BJ Franke KA McCracken JE Effective use of liquid chemical germicides on medical devices: instrument design problems.in: 4th ed. Disinfection, sterilization, and preservation. : Lea and Febiger, Philadelphia1991: 1097-1106Google Scholar, 29DiMarino AJ Bond WW Flexible gastrointestinal endoscopic reprocessing.Gastrointest Endosc. 1996; 43: 522-524Google Scholar Although the newer reprocessing agents are highly efficacious, little comparative data have emerged and two of the three reviewed articles suggest variable3Barbee SL Weber DJ Sobsey MD Rutala WA Inactivation of Cryptosporidium parvum oocyst infectivity by disinfection and sterilization processes.Gastrointest Endosc. 1999; 49: 605-611Google Scholar or lack2Cronmiller JR Nelson DK Salman G Jackson D 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 Scopus (41) Google Scholar of incremental benefit in experimental settings. Reprocessing and infection control in GI endoscopy have advanced substantially in the past two decades. Further progress will require (1) universal adoption of currently prescribed regimens, (2) advances in endoscope design to improve access for verifiable cleaning, (3) development or adaptation of emerging sterilization technologies to endoscope materials and design, and (4) experimental and clinical outcome data to justify new methods which will undoubtedly increase costs. In the meantime, outcome data should be sought for the recently established guidelines before resorting to their wholesale rejection, and quality assurance programs within individual facilities should emphasize their resolute application.