摘要Background Pseudomonas aeruginosa is a common conditional pathogen in newborn infant wash water,which can cause severe infections in neonates through direct contact or inhalation of aerosols.This study aimed to evalu-ate the disinfection efficacy of 0.4％hydrogen peroxide against P.aeruginosa contamination in newborn wash wa-ter and determine the optimal disinfection cycle.Methods Pipelines were disinfected for 8 hours using a 0.4％hydrogen peroxide solution.Cold water was con-tinuously monitored from five infant wash basins across four wards in the neonatal department for 12 weeks,with samples collected before disinfection,1 day after disinfection,and weekly thereafter.The water samples were cul-tured at 35-37 ℃ for 48 hours,colony counts were recorded,and P.aeruginosa was identified using mass spec-trometry.After determining the disinfection cycle,further monitoring and validation were conducted.Results There was a 100％qualification rate in the first 3 weeks following the disinfection procedure.However,an obvious increase in the disqualification rate was observed in the fourth week.A second validation confirmed a similar trend,which indicates an elevated risk of recurring contamination after a 4-week disinfection cycle.Conclusion The 8-hour soaking method using 0.4％hydrogen peroxide demonstrated short-term efficacy and was suitable for high-frequency disinfection of newborn wash water.This study provides scientific evidence for the prevention and control of P.aeruginosa contamination in neonatal wash water,and emphasizes the impor-tance of multidimensional interventions.