Mancini, Benedetta Scurti, Maria Dormi, Ada Grottola, Antonella Zanotti, Andrea Cristino, Sandra Effect of Monochloramine Treatment on Colonization of a Hospital Water Distribution System by Legionella spp.: A 1 Year Experience Study Contamination of hot water distribution systems by Legionella represents a great challenge due to difficulties associated with inactivating microorganisms, preserving the water characteristics. The aim of this study was to examine over the course of 1 year in 11 fixed sites, the impact of monochloramine disinfection on Legionella, heterotrophic bacteria (36 °C), Pseudomonas aeruginosa contamination, and chemical parameters of a plumbing system in an Italian hospital. Three days after installation (T0), in the presence of monochloramine concentration between 1.5 and 2 mg/L, 10/11 sites (91%) were contaminated by L. pneumophila serogroups 3 and 10. After these results, the disinfectant dosage was increased to between 6 and 10 mg/L, reducing the level of Legionella by three logarithmic unit by 2 months postinstallation (T2) until 6 months later (T3). One year later (T4), there was a significant reduction (<i>p</i> = 0.0002) at 8/11 (73%) sites. Our data showed also a significant reduction of heterotrophic bacteria (36 °C) in 6/11 (55%) sites at T4 (<i>p</i> = 0.0004), by contrast the contamination of P. aeruginosa found at T0 in two sites persisted up until T4. The results of the present study show that monochloramine is a promising disinfectant that can prevent Legionella contamination of hospital water supplies. 2 months postinstallation;pneumophila serogroups 3;logarithmic unit;aeruginosa;Legionella contamination;monochloramine disinfection;bacteria;T 4;T 0;disinfectant dosage;1 year;water characteristics;plumbing system;chemical parameters;6 months;Italian hospital;mg;Hospital Water Distribution System;site;water distribution systems;hospital water supplies;monochloramine concentration;study show;T 4.;Monochloramine Treatment;heterotrophic;inactivating microorganisms;1 Year Experience StudyContamination 2015-04-07
    https://acs.figshare.com/articles/journal_contribution/Effect_of_Monochloramine_Treatment_on_Colonization_of_a_Hospital_Water_Distribution_System_by_Legionella_spp_A_1_Year_Experience_Study/2179495
10.1021/es506118e.s001