Management and microbial monitoring of final rinse water for flexible endoscopes in 290 hospitals in Jiangsu Province, China: a multicenter cross-sectional study.

Background: There is a lack of a universally accepted standard or guideline for the frequency of disinfection in purified water pipelines. Furthermore, there is no standardized method for detecting microorganisms in the final rinse water utilized for endoscope cleaning.This study aims to examine the current management and microbial monitoring practices concerning the final rinse water used for flexible endoscope cleaning in medical institutions.

Methods: A questionnaire was designed using a convenience sampling method to gather data on the maintenance and microbial monitoring of final rinse water for flexible endoscopes in 290 medical institutions across Jiangsu Province, China.

Results: Purified water is used for endoscope rinsing by 93.45% of institutions, with 78.62% employing centralized water supply. Membrane filtration devices at the terminal are installed by 82.07%, mainly with a 0.2μm pore size (76.47%), and are replaced quarterly (32.77%). Disinfection devices are present at 52.76% of terminals, with varied disinfection frequencies; chlorine-containing disinfectants (48.15%) and peracetic acid (34.92%) are predominant. Inadequate disinfection, filter membrane neglect, sampling contamination, and biofilm formation are identified as reasons for non-compliant final rinse water. Actions include filter replacement, pipeline disinfection, and flushing. Microbial mornitoring occurs quarterly (70.96%), with faucet outlets as primary sampling sites. Standards are based on 10cfu/100ml (87.58%), using membrane filtration (40.81%) and nutrient agar plates (82.72%). A cultivation period of 2 days predominated (72.43%), with a temperature range of 35-37°C (76.47%).

Conclusion: While purified water and terminal filters are common for final rinsing of endoscopes, there is variation in maintenance and supply line disinfection. Current microbiological methods' reliability is considered low, necessitating further research to establish unified standards for effective endoscope final rinse water management and monitoring.