Elimination of biofilm and microbial contamination reservoirs in hospital washbasin U-bends by automated cleaning and disinfection with electrochemically activated solutions

Summary Background Washbasin U-bends are reservoirs of microbial contamination in healthcare environments. U-bends are constantly full of water and harbour microbial biofilm. Aim To develop an effective automated cleaning and disinfection system for U-bends using two solutions generated by electrochemical activation of brine including the disinfectant anolyte (predominantly hypochlorous acid) and catholyte (predominantly sodium hydroxide) with detergent properties. Methods Initially three washbasin U-bends were manually filled with catholyte followed by anolyte for five minutes each once weekly for five weeks. A programmable system was then developed with one washbasin that automated this process. This U-bend had three cycles of five minutes catholyte followed by five minutes anolyte treatment a week for three months. Quantitative bacterial counts from treated and control U-bends were determined on blood agar (CBA), R2A, PAS and PA agars following automated treatment and on CBA and R2A following manual treatment. Findings The average bacterial density from untreated U-bends throughout the study was >1 x 105 CFU/swab on all media with Pseudomonas aeruginosa accounting for approximately 50% of counts. Manual U-bend ECA treatment reduced counts significantly (