Dziewulski DM, Ingles E, Codru N, Strepelis J, Schoonmaker-Bopp D. Use of copper-silver ionization for the control of legionellae in alkaline environments at health care facilities.
Am J Infect Control 2015;
43:971-6. [PMID:
26149750 DOI:
10.1016/j.ajic.2015.05.018]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 05/12/2015] [Accepted: 05/12/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND
There are multiple treatment options for the control of legionellae in premise hot water systems. Water chemistry plays a role in the efficacy of these treatments and should be considered when selecting a treatment. This study demonstrated the efficacy of copper-silver ionization (CSI) under alkaline water conditions in 2 health care facilities.
METHODS
Monitoring for copper (Cu) and silver (Ag) ions was performed, and the corresponding percentage of positive Legionella cultures was monitored. Low Legionella colony forming units (CFU), with a mean <10 CFU/100 mL, and ≤30% positive culture for each sampling period, along with no recurrent disease, were considered indicative of control.
RESULTS
CSI treatment was shown to reduce both the number of CFU found and the percentage of samples found to be culture positive. After treatment was established, culture positivity was, for example, reduced from 70% (>10(3) CFU/100 mL) to consistently <30% (38 CFU/100 mL).
CONCLUSION
Control of legionellae in premise water systems may be a complex process requiring long-term assessments for adequate control. This work found that CSI could be successful in controlling Legionella under alkaline water conditions, and the evidence suggests that Ag ions are responsible for the control of Legionella pneumophila 1, L pneumophila 6, and L anisa.
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