Four-Year Environmental Surveillance Program of spp. in One of Palermo's Largest Hospitals.

is a ubiquitous bacterium that lives in freshwater environments and colonizes human-made water systems. is the most virulent species, and risk factors for Legionnaires' disease include increasing age, smoking, chronic diseases, and immunodeficiency. For this reason, it is very important to assess and monitor hospital water systems in order to prevent legionellosis. We have monitored a large hospital in Palermo for four years. To determine the presence of microorganisms, according to national guidelines, we used the culture method, which is considered the gold standard for detection. Sampling was divided into five macro-areas, and a total of 251 samples were collected during the period of investigation, 49% of which were spp.-positive and 51% were spp.-negative. Positive samples with . sgr 2-15 were most frequent in the Underground (55.6%, = 0.0184), Medicine (42.9%, = 0.0184) and Other (63.2%, = 0.002) areas; while positive samples for sgr 1 were less frequent in the Underground (0.0%, = 0.0184) and Surgery areas (4.5%, = 0.033), and for , were less frequent in the Medicine (4.1%, = 0.021), Oncohematology (0.0%, = 0.0282), and Other (0.0%, = 0.016) areas. Finally, no significant differences were observed among the areas for each isolate considered. The surveillance carried out in these years demonstrates the importance of monitoring, which allows us to analyze the conditions of hospital facilities and, therefore, prevent spp. infections.