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keeping Legionella out of water systems
Author(s) -
Sidari Frank P.,
Stout Janet E.,
Vanbriesen Jeanne M.,
Bowman Ann Marie,
Grubb Douglas,
Neuner Alan,
Wagener Marilyn M.,
Yu Victor L.
Publication year - 2004
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.2004.tb10538.x
Subject(s) - legionella , legionnaires' disease , medicine , water source , disease control , chlorine dioxide , environmental science , emergency medicine , chemistry , legionella pneumophila , environmental health , water resource management , biology , bacteria , inorganic chemistry , genetics
Hospitals are often required to perform a supplemental disinfection of their water systems to protect individuals from hospital‐acquired Legionnaires' disease. The authors of this article recently studied one hospital where three cases of hospital‐acquired Legionnaires' disease were detected in less than two years. These cases were linked to Legionella colonization of the hospital's water system. Chlorine dioxide (ClO 2 ) was considered a cost‐effective approach to disinfection given that ClO 2 generators could treat the 23 buildings comprising the hospital complex from one central location. The authors evaluated the efficacy of maintaining a residual of 0.5 to 0.8 mg/L of ClO 2 for Legionella control in the secondary distribution system of this 437‐bed hospital over a two‐year period. Monthly monitoring showed mean Legionella positivity at hot water outlets and cold building source water areas decreased from 23 to 12% and 9 to 0%, respectively ( p < 0.05). ClO 2 residuals decreased with increasing distance from the application point and temperature. Mean ClO 2 concentrations were lowest in hot water outlets (0.08 mg/L) followed by cold water outlets (0.33 mg/L) and reservoirs (0.68 mg/L). Complete eradication (0% positivity) of Legionella was achieved after 1.75 years, and no cases of Legionnaires' disease were reported during this time.