RISK OF CONTAMINATION OF STERILE BIOPSY FORCEPS IN DISINFECTED ENDOSCOPES

Background: Previous studies have shown that pathogens may persist wit hin bacterial biofilms in endoscope accessory channels despite high-le vel disinfection. Breaching the gastrointestinal mucosa with biopsy fo rceps contaminated at time of passage has the potential to cause cross -infection between patients. Methods: We studied contamination risk of sterilized biopsy forceps passed through endoscopes after high-level disinfection. For each trial, five video colonoscopes, duodenoscopes, and gastroscopes were used. All endoscopes had been previously process ed and stored for 10 or move hours. Sterile biopsy forceps were insert ed and retrieved followed by vortexing the tips in 15 mt of soy broth. Under a laminar flow hood, the broth was filtered through a 0.2 mu m millipore membrane and plated. Because of minimal bacterial growth res ulting from the above, soy broth (> 20 mt) was flushed through two vid eo colonoscopes, duodenoscopes, and gastroscopes on two occasions and collected. The effluent was plated using a sample of 0.1 mt dilution. The remaining suspension was passed through a millipore filter, and th e filter was cultured. All cultures were incubated more than 48 hours. Results: Biopsy forceps underwent a total of 24 anaerobic and 75 aero bic cultures. Microbacterial growth occurred on 17 plates: 7 from gast roscopes, 5 from colonoscopes, and 5 from duodenoscopes. Fifteen plate s grew staphylococcus for a total of 21 colonies, 1 plate grew 1 colon y of propionibacter, 2 plates grew diphtheroids for a total of 4 colon ies, and 1 plate grew a single colony of lactobacillus. Cultures from soy broth flushed through the various endoscopes grew on 5 plates: 3 f rom gastroscopes and 2 from duodenoscopes grew a total of 8 colonies o f staphylococcus. Conclusions: With proper cleaning technique, a 20-mi nute soak in 2% glutaraldehyde is effective in disinfecting endoscopes . Although current procedures for endoscope disinfection remain imperf ect, we found that in this clinical setting, infection of pathogenic g astrointestinal flora is unlikely when using sterile biopsy forceps.