Endoscopy water source: tap or sterile water?

The purpose of this study was to determine whether the endoscopic water source holds potential for transmission of pathogens. Phase I of the study used tap water and clean water bottles; Phase II used sterile water and steam-sterilized water bottles. In both phases, a control bottle filled with water from the appropriate source was set up. Cultures were taken from both the controls and endoscopy water sources before the day's procedures were started and at the end of the day. Each phase contained 100 to 106 sets of samples. Many of the tap water samples were positive for normal flora found in city water sources. No clinically significant complications were identified during either phase of the study. The use of tap water and clean water bottles was found to carry no greater risk than using sterile water and sterile bottles. The practice of using tap water will result in significant cost savings. Further study will be needed to look at the integrity of the endoscope and water bottle design in preventing transmission of pathogens.