OBJECTIVE: To assess the safety and efficacy of a chlorine dioxide water treatment system in controlling Legionella in a hospital water supply. DESIGN: For 17 months following installation of the system, we performed regular water cultures throughout the building, assessed chlorine dioxide and chlorite levels, and monitored metal corrosion. RESULTS: Sites that grew Legionella species decreased from 41% at baseline to 4% (P = .001). L. anisa was the only species recovered and it was found in samples of both hot and cold water. Levels of chlorine dioxide and chlorite were below Environmental Protection Agency (EPA) limits for these chemicals in potable water. Further, enhanced carbon filtration effectively removed the chemicals, even at chlorine dioxide levels of more than twice what was used to treat the water. After 9 months, corrosion of copper test strips exposed to the chlorine dioxide was not higher than that of control strips. During the evaluation period, there were no cases of nosocomial Legionella in the building with the system, whereas there was one case in another building. CONCLUSIONS: Our results indicate that operation of a chlorine dioxide system effectively removed Legionella species from a hospital water supply. Furthermore, we found that the system was safe, as levels of chlorine dioxide and chlorite were below EPA limits. The system did not appear to cause increased corrosion of copper pipes. Our results indicate that chlorine dioxide may hold promise as a solution to the problem of Legionella contamination of hospital water supplies.
OBJECTIVE: To assess the safety and efficacy of a chlorine dioxide water treatment system in controlling Legionella in a hospital water supply. DESIGN: For 17 months following installation of the system, we performed regular water cultures throughout the building, assessed chlorine dioxide and chlorite levels, and monitored metal corrosion. RESULTS: Sites that grew Legionella species decreased from 41% at baseline to 4% (P = .001). L. anisa was the only species recovered and it was found in samples of both hot and cold water. Levels of chlorine dioxide and chlorite were below Environmental Protection Agency (EPA) limits for these chemicals in potable water. Further, enhanced carbon filtration effectively removed the chemicals, even at chlorine dioxide levels of more than twice what was used to treat the water. After 9 months, corrosion of copper test strips exposed to the chlorine dioxide was not higher than that of control strips. During the evaluation period, there were no cases of nosocomial Legionella in the building with the system, whereas there was one case in another building. CONCLUSIONS: Our results indicate that operation of a chlorine dioxide system effectively removed Legionella species from a hospital water supply. Furthermore, we found that the system was safe, as levels of chlorine dioxide and chlorite were below EPA limits. The system did not appear to cause increased corrosion of copper pipes. Our results indicate that chlorine dioxide may hold promise as a solution to the problem of Legionella contamination of hospital water supplies.
Authors: Isabella Marchesi; Greta Ferranti; Antonella Mansi; Anna M Marcelloni; Anna R Proietto; Navneet Saini; Paola Borella; Annalisa Bargellini Journal: Appl Environ Microbiol Date: 2016-05-02 Impact factor: 4.792
Authors: Benjamin J Silk; Jennifer L Foltz; Kompan Ngamsnga; Ellen Brown; Mary Grace Muñoz; Lee M Hampton; Kara Jacobs-Slifka; Natalia A Kozak; J Michael Underwood; John Krick; Tatiana Travis; Olivia Farrow; Barry S Fields; David Blythe; Lauri A Hicks Journal: BMC Infect Dis Date: 2013-06-27 Impact factor: 3.090