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

SummaryBackgroundWashbasin U-bends are reservoirs of microbial contamination in healthcare environments. U-Bends are constantly full of water and harbour microbial biofilm.AimTo 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.MethodsInitially three washbasin U-bends were manually filled with catholyte followed by anolyte for 5 min 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 5 min catholyte followed by 5 min anolyte treatment per 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.FindingsThe average bacterial density from untreated U-bends throughout the study was >1×105 cfu/swab on all media with Pseudomonas aeruginosa accounting for ∼50% of counts. Manual U-bend electrochemically activated (ECA) solution treatment reduced counts significantly (<100 cfu/swab) (P < 0.01 for CBA; P < 0.005 for R2A). Similarly, counts from the automated ECA-treatment U-bend were significantly reduced with average counts for 35 cycles on CBA, R2A, PAS, and PA of 2.1 ± 4.5 (P < 0.0001), 13.1 ± 30.1 (P < 0.05), 0.7 ± 2.8 (P < 0.001), and 0 (P < 0.05) cfu/swab, respectively. P. aeruginosa was eliminated from all treated U-bends.ConclusionAutomated ECA treatment of washbasin U-bends consistently minimizes microbial contamination.