Endowashers: an overlooked risk for possible post-endoscopic infections

Background: Prevention of post-endoscopy infections is an important objective to assure patient safety. Endowashers, or high throughput irrigation water pumps, are a frequently used device on endoscopes. Recommendations published by professional bodies and regulatory health agencies cover not only adequate reprocessing of fiber-endoscopes but also state accepted methods of regular microbial sampling. Although major instruments like endoscopes are covered by these recommendations, other devices used as optional add-ons for endoscopes are not included. Objective: The aim of this prospective study was to investigate the potential for endowashers to act as a possible source of infection. Method: 24 endowashers were sampled. Sterile rinse-water was pumped through the endowasher and tested microbiologically according to standardised tests. Sampling was performed in 18 hospitals, including 2 university teaching hospitals, in northern Germany. If endowashers were contaminated, devices were reprocessed and re-tested. Results: Of 44 samples, 6 (14%) were contaminated with pathogens of up to >20,000 cfu/ml. Pseudomonas aeruginosa and other Gram-negative non-fermenters such as Stenotrophomonas spp. (18x) and Acinetobacter spp. (2x), followed by Staphylococcus aureus (1x), Enterobacter cloacae (1x), Candida albicans (1x), Serratia spp. (1x), Streptococcus spp. (1x) and others (2x). Conclusion: Endowashers can be a potential source of infection. Despite their common use, they are not routinely sampled microbiologically. Endowashers should be clearly mentioned in respective guidelines and routine quality control sampling of endowashers should be part of such recommendations. If endowashers are not monitored regularly, devices with single-use hoses should be used.