Surveillance culture monitoring of double-balloon enteroscopy reprocessing with high-level disinfection

Background Inadequate reprocessing of double-balloon enteroscopy (DBE) or of endoscopic accessories may result in iatrogenic infections and present a risk to public health. Aim To use microbiological surveillance culture monitoring (SCM) to assess the adequacy of high-level disinfection (HLD) with standard reprocessing procedures of DBE. Materials and methods We performed a prospective study on cultures collected from DBEs that had been treated by HLD by an automated endoscope washing machine (AEWM) decontamination cycle. This study included 42 cases with 57 cultures, which were collected consecutively between October 2009 and December 2010. In 31 cases, 31 cultures were collected from oral route DBE (mean patient age, 68·9years), and in 23 cases, 26 cultures were collected from anal route DBE (mean patient age, 67·9years). The results obtained were compared with those of our previous study of SCM on gastroscopy (GS) and colonoscopy (CS). The samples were collected by flushing 50mL sterile distilled water into the suction channel and collecting the flow-through in a sterile container. The samples were then incubated at 37°C and examined for bacterial growth. Results Before HLD, the positive culture rate was 83·9% (26/31) for the oral route DBE and 100% (26/26) for the anal route DBE (P=0·0406). After HLD, the positive culture rate was 12·9% (4/31) for the oral route DBE and 19·2% (5/26) for the anal route DBE (P>0·05). A linear trend relationship was found between positive SCM and the length and category of diagnostic instruments - GS, CS, oral route DBE and anal route DBE. Conclusions Surveillance culture monitoring is a useful method to assess the effectiveness of HLD reprocessing of DBE. Machine washing may not achieve complete disinfection. Using AEWM regularly is mandatory to minimize cross-contamination and to ensure quality assurance. Additional procedures are necessary to employ for the longer and anal route DBE.