The purpose of this study is to report the experience of the implementation and application of a 3-year Water Safety Plan (WSP) together with the secondary disinfection of water by monochloramine to control and prevent healthcare-associated legionellosis in an Italian hospital strongly colonized by . Risk assessment was carried out by the WSP team. The main critical control points focused on in developing the WSP for the control of was the water distribution system. A sampling plan for the detection of was implemented. A widespread contamination of the hot water distribution system by sg5 was found. Results after 3 years of the continuous disinfection of hot water with monochloramine indicate the eradication of . The implementation and application of a WSP in a hospital, together with the disinfection of the water distribution system with monochloramine, can be effective in controlling the growth of and in preventing nosocomial legionellosis.
