Treatment of a Legionella pneumophila-colonized water distribution system using copper-silver ionization and continuous chlorination

Infect Control Hosp Epidemiol. 1999 Jun;20(6):426-8. doi: 10.1086/501645.


The detection in April 1997 of a case of nosocomial legionellosis in our hospital led to the discovery that both our hot- and cold-water circuits were heavily colonized with Legionella pneumophila. Conventional methods for eradication of the organisms were unsuccessful, so a copper-silver (Cu-Ag) ionization system and a continuous chlorination system were installed. Five months later, the number of colonized sites decreased from an initial 58.3% to 16.7%.

MeSH terms

  • Chlorine
  • Cross Infection / diagnosis
  • Cross Infection / prevention & control*
  • Decontamination / methods*
  • Humans
  • Infection Control / methods
  • Legionella pneumophila* / isolation & purification
  • Legionnaires' Disease / diagnosis
  • Legionnaires' Disease / prevention & control*
  • Water Microbiology*
  • Water Supply*


  • Chlorine