Dr. Markovitz's report was reviewed, but our article only included infections transmitted by flexible, not rigid, fiberoptic bronchoscopes.

We disagree with Drs. Benjamin and Bond that "universal use of effective disinfection" exists and believe that "recognized and reported cases probably represent a minority of all infections transmitted by endoscopy". Seven studies published since 1988 show that major problems still exist regarding compliance with accepted cleaning and disinfection guidelines. In a recent collaborative effort (which included the Food and Drug Administration), investigators found numerous fundamental errors in cleaning and disinfection procedures [1]. Moreover, among cultures taken from endoscopes deemed ready for use in a patient, 23.9% grew 100 000 or more colonies of bacteria [1]. Further, in a survey published in 1991 involving a mailing to all members of the SGNA, 6% (n = 116) of the respondents reported endoscopy-related infections, most from private practice settings [2]. Previously published reports had come almost exclusively from academic centers, and because numerous case reports have already been described in the literature, there is currently little incentive for submitting or publishing an additional isolated case report. Finally, for the reasons mentioned in our article, sporadically occurring endoscopy-related infections, especially those with long incubation periods, are difficult to recognize.

We clearly stated that "most routinely used disinfectants inactivate HIV" and "endoscopic transmission of HIV has not been reported". Nevertheless, if effective cleaning and disinfection procedures are not done, any organism can theoretically be transmitted. As pointed out by Katner and colleagues [3], approximately 1900 of the family physicians they surveyed disinfected their sigmoidoscopes in a manner that has not been shown to inactivate HIV.

In reply to the members of SGNA, we agree that practitioners should be familiar with the guidelines established by SGNA and ASGE. In our article, we singled out guidelines from the Association for Practitioners in Infection Control and the World Congress of Gastroenterology because of their balanced committee membership. Moreover, the latter committee, which included next year's president of ASGE (D. E. Fleischer), provided easy-to-understand, step-by-step guidelines. We urge caution in relying solely on manufacturers' instructions for the use of disinfectants. In a recent Environmental Protection Agency study [4], uncertainty was expressed about label claims on many currently marketed disinfectants. They also estimated that up to 20% of disinfectants on the market might be ineffective [4].

There is nothing misleading about the data presented in Tables 1,2, and 3. We agree that most reported cases occurred before 1985, but two recent studies [1, 5] involved post-1985 instruments and showed contamination of gastrointestinal endoscopes following cleaning and disinfection.