Janet E. Stout, Yu-Sen E. Lin, Angella M. Goetz, Robert R. Muder
Cambridge University Press, Infection Control and Hospital Epidemiology, December 1998
This study evaluated the efficacy of superheat-and-flush and copper-silver ionization for Legionella control in an acute care hospital. The hospital had been using the superheat-and-flush method for 13 years but was still experiencing incidences of Legionnaires’ disease.
Legionnaires’ cases decreased once the copper-silver ionization system was installed, with no cases reported in the last year evaluated by the study (1997). The average number of Legionnaires’ cases from 1979 to 1996 are included below.
- 1979-1981 (no disinfection method): 25 cases per year
- 1982-1994 (superheat-and-flush method): 6 cases per year
- 1995-1997 (copper-silver ionization method): 2 cases per year
Copper-silver ionization was found to be more effective in controlling Legionella than superheat-and-flush. The study notes that hospitals must conduct routine Legionella testing and closely monitor ion concentrations for copper-silver ionization to remain effective.