The Facts On Legionella and Legionnaires Disease

What is Legionella?

Legionella is a naturally occurring bacterium and is present in bodies of water and soil. It often inhabits warm and wet environments such as potable water systems and infrequently used water fixtures and also grows in cold water systems.

Legionella bacteria can cause Legionnaires’ Disease, a dangerous waterborne disease that accounts for thousands of hospital admissions and a growing number of fatalities annually in the United States today.

How Do You Get Legionnaires’ Disease?

Legionnaires Disease is caused by breathing in small water droplets contaminated with Legionella. It does not spread from person-to-person contact, nor is it airborne. People contract Legionnaires’ disease, a severe lung infection, by aspirating, or breathing in, water vapor infected with the Legionella bacteria.

Legionnaires’ disease can be fatal if not treated promptly. Legionella control should be in the water management plan and regular risk assessments of all facilities using water.

What Are the Symptoms of Legionnaires’ Disease?

Legionella entering biofilm illustration Enrich Products, Inc

What Are the Symptoms of Legionnaires’ Disease?

Legionnaires Disease is a form of Pneumonia. Symptoms typically appear 2 to 10 days after exposure to water contaminated with Legionella. 

Initial Signs and Symptoms:

  • Headache
  • Muscle aches
  • Fever that may be 104 F (40 C) or higher

Advanced Sign and Symptoms Appearing After 2-3 Days

  • Cough, which might bring up mucus and sometimes blood
  • Shortness of breath
  • Chest pain
  • Gastrointestinal symptoms, such as nausea, vomiting, and diarrhea
  • Confusion or other mental changes

A mild form of Legionnaires’ disease – known as Pontiac fever – can produce fever, chills, headache, and muscle aches. Pontiac fever doesn’t infect your lungs, and symptoms usually clear within two to five days.

Treatments for Legionnaires’ Disease use antibiotics to fight the symptoms and may require breathing assistance from a ventilator. The risk of Legionnaires Disease is higher for those already in a hospital or with chronic diseases.

When to Seek Medical Attention?

Please contact your doctor if you are experiencing the symptoms listed above or if you suspect you’ve been exposed to Legionella bacteria. Early diagnosing and treating Legionnaires’ Disease can help shorten the recovery period and prevent serious complications. Certain people are at higher risk, such as smokers, people over 50 years of age, or those with weakened immune systems. Prompt treatment is critical.

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Copper-Silver Ionization Studies



1943 Benedum Hall, University of Pittsburgh, Pittsburgh, PA 15261, USA

2Veteran Affairs Medical Center, Pittsburgh, Pa 15240, USA

Abstract – Copper-silver ionization is a new disinfection method that is being used to eradicate Legionella pneumophila from the hospital hot water recirculating systems. The objective of this study was to determine the susceptibility of L.pneumophila serogroup 1 to copper and silver ions alone and in combination. L. pneumophila serogroup 1 (L.p. sg- 1) was completely inactivated (6-log reduction) at copper concentrations of 1 mg/l within 2.5 h, whereas more than 24 h was required to achieve a similar reduction at the highest silver ion concentration tested (0.08 mg/l). Checkerboard method and Gard additive model prediction demonstrated that copper and silver ions in combination could result in additive or synergistic effect depending on the concentration of copper and silver ions. Under the experimental conditions used in this study, synergism of copper/silver ions in eradicating was observed at higher concentration combinations of copper/silver ions (e.g. 0.4/0.04 mg/l) while only an additive effect was observed at lower concentrations combinations (e.g. 0.2/0.02 mg/l). This study suggested that both copper and silver ions are effective in inactivating L. pneumophila and the combined effect is greater than that seen with either ion alone. Copyright © 1996 Elsevier Science Ltd.

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Experiences of the First 16 Hospitals Using Copper-Silver Ionization for Legionella Control: Implications for the Evaluation of Other Disinfection Modalities

Janet E. Stout, PhD; Victor L. Yu, MD

Vol. 24 No. 8 Infection Control and Hospital Epidemiology

Stated in the ABSTRACT on the first page:

BACKGROUND AND OBJECTIVES: “Hospital-acquired legionnaires’ disease can be prevented by disinfection of hospital water systems. This study assessed the long-term efficacy of copper-silver ionization as a disinfection method in controlling Legionella in hospital water systems and reducing the incidence of hospital-acquired legionnaires’ disease. A standardized, evidence-based approach to assist hospitals with decision making concerning the possible purchase of a disinfection system is presented.

RESULTS: “All 16 hospitals reported cases of hospital-acquired legionnaires’ disease prior to installing the copper-silver ionization system.” No cases of hospital-acquired legionnaires‘ disease have occurred in any hospital since 1995.

CONCLUSIONS: “This study represents the final step in a proposed 4-step evaluation process of disinfection systems that includes (1) demonstrated efficacy of Legionella eradication in vitro using laboratory assays, (2) anecdotal experiences in preventing legionnaires’ disease in individual hospitals, (3) controlled studies in individual hospitals, and (4) validation in confirmatory reports from multiple hospitals during a prolonged time (5 to 11 years in this study). Copper-silver ionization is now the only disinfection modality to have fulfilled all four evaluation criteria(Infect Control Hosp Epidemiol 2003;24:563-568).”

Stated on page 5 the last two paragraphs in the 2nd column:

“Advantages of copper-silver ionization are that it is more cost-effective than hyperchlorination, is easier to maintain, and does not corrode piping or plumbing fixtures, and in the event of mechanical failure, recontamination is delayed for weeks, allowing a safety buffer.33-35 In contrast, if a chlorinator fails, recontamination occurs rapidly.’

“The four evaluation criteria listed earlier have now been fulfilled for copper-silver ionization. We recommend that this process of evaluation be applied to other newer disinfection approaches such as those involving chlorine dioxide and monochloramine. It may be several years before sufficient controlled trials of these modalities are available for scientific scrutiny. This study documents the long-term efficacy of copper-silver ionization in reducing Legionella in hospital hot water distribution systems, as well as reducing or eliminating cases of hospital-acquired legionnaires disease.”

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About Enrich Products, Inc

Since 1997, Enrich Products has been providing healthcare, hospitality, and other communities with Copper-Silver Ionization for the control of Legionella in potable water systems. EPI equipment is proudly manufactured in Pittsburgh, PA and distributed throughout North America.


919 Penn Avenue
Pittsburgh, PA 15221
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