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Control of Legionella contamination in a hospital water distribution system by monochloramine

Isabella Marchesi1, Stefano Cencetti, Patrizia Marchegiano

  • 1Department of Public Health Sciences, University of Modena and Reggio Emilia, Italy.

American Journal of Infection Control
|July 12, 2011
PubMed
Abstract

Insights

Monochloramine effectively controlled Legionella pneumophila in hospital water systems over one year. This disinfectant significantly reduced contamination compared to baseline and chlorine dioxide, offering a promising alternative for building water safety.

Area of Science:

  • Environmental Microbiology
  • Water Treatment Technologies
  • Hospital Infection Control

Background:

  • Legionella pneumophila poses a significant risk in hospital water systems.
  • Controlling Legionella pneumophila contamination is crucial for patient safety.
  • Existing disinfection methods may have limitations.

Purpose of the Study:

  • To evaluate the efficacy of monochloramine for controlling Legionella pneumophila.
  • To compare monochloramine disinfection with chlorine dioxide in a hospital setting.
  • To assess the long-term impact of monochloramine on water system contamination.

Main Methods:

  • Continuous monochloramine distribution in a hospital hot water system.
  • Monitoring Legionella pneumophila and Pseudomonas spp. contamination.
  • Comparative analysis with chlorine dioxide in parallel water networks.

Main Results:

  • Monochloramine reduced contaminated sites from 97.0% to 13.3%.
  • Significant reduction observed compared to baseline and chlorine dioxide (56.7% and 60.8%).
  • No positive samples exceeded 10(4) CFU/L post-treatment, a marked improvement from baseline (59.4%).

Conclusions:

  • Monochloramine is a highly effective disinfectant for Legionella pneumophila.
  • It presents a viable and potentially superior alternative to chlorine dioxide.
  • Recommended for controlling legionellae in diverse building water systems.

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