Results of Monitoring Terminal Cleaning and Disinfection Through Three Distinct Methodologies in a Private Institution in Curitiba

Periodic validation of terminal cleaning and disinfection methods contributes to reducing microbial load on surfaces and preventing cross-transmission of microorganisms. To analyze results of terminal disinfection monitoring in a 186-bed private hospital in Curitiba-PR between May/2024 and May/2025. Terminal disinfection monitoring is adopted in the institution as part of the hospital infection control program and includes the most frequently touched surfaces, mainly in ICUs. Three methodologies are used: (a) surface culture collection using a swab soaked in saline, rubbed on a demarcated surface equivalent to an A4 sheet of paper; acceptable reference value includes negative or positive with skin contaminant microorganism; (b) surface ATP (adenosine triphosphate) measurement by bioluminescence, with an internally standardized reference value of <30 relative light units (RLU); (c) application of invisible fluorescent spray under natural light, followed by inspection with ultraviolet light, with acceptable result being absence of marking after cleaning. ATP and fluorescent spray results are immediately reported to the team for process adjustments. Environmental culture results are compiled by the infection control team and discussed with responsible teams to identify improvement opportunities. In 115 cultures after nursing cleaning, 3 samples (2.6%) were positive for relevant microorganisms and 21 for non-relevant microorganisms (18.26%). In 144 cultures from surfaces cleaned by the cleaning team, 5 samples were positive for relevant microorganisms (3.47%) and 18 non-relevant (12.50%). Relevant microorganisms identified included: P. aeruginosa, P. putida, P. nitroreducens, S. aureus, A. baumannii, K. pneumoniae, E. cloacae, S. maltophilia. Regarding ATP results, among 384 applications, 21 (5.4%) had results >30 RLU. For fluorescent marker application, among 624 evaluations, only 4 (0.6%) were noncompliant. Monitoring environmental results with analysis and identification of improvement opportunities contributes to maintaining a safe process that helps reduce the risk of microorganism transmission in the hospital environment.