Outbreak of glutaraldehyde-induced proctocolitis

Background: An outbreak of hemorrhagic proctocolitis occurred after the introduction of 2% glutaraldehyde as a disinfectant for colonoscopes. An inadequate rinsing procedure was detected. Recent studies have pointed to glutaraldehyde as an irritant potentially capable of inducing colitis. This study aimed to measure retrospectively the occurrence of proctocolitis after colonoscopy in persons exposed to glutaraldehyde used as a disinfectant for colonoscopes, and to compare this rate with that in patients exposed to the previous cleaning procedure. Methods: Colonoscopic procedures were randomly selected during the period when glutaraldehyde was used, as well as during the previous period, when a detergent was used. Patients were asked to respond to a questionnaire during a telephone interview, in search of symptoms compatible with proctocolitis after colonoscopy. Results: Of the 400 colonoscopic procedures selected during each of the glutaraldehyde and the detergent periods, respectively 299 and 242 were evaluable. According to different nonexclusive definitions, we observed in the glutaraldehyde period higher frequencies of proctocolitis (at least five stools/day; 14/299 vs 3/242, p = 0.02), severe proctocolitis (> 10 stools/day; 10/299 vs 1/242, p = 0.04), and severe hemorrhagic proctocolitis (6/299 vs 0/242, p = 0.04). Younger age was associated with proctocolitis only during the glutaraldehyde period (p = 0.0008). No pathogen was demonstrated in the only two patients who had stool cultures. The median incubation after colonoscopy was 4 hours (range 0 to 24 hours) and the symptoms lasted 30 hours (range 6 to 216 hours). No patient had fever, and the illness resolved spontaneously in all cases. Conclusion: Inadequate rinsing of colonoscopes after immersion in glutaraldehyde may result in proctocolitis, presumably caused by direct action on the mucosa.