Legionella

To understand how DCW generators and in-house disinfectant NEUTHOX®  work to control and prevent bacteria in water in an eco-friendly, economical and energy-efficient way, let’s take a look at Legionella, one of the most widespread bacteria found in natural water systems. 

Legionella is the causative agent of Legionnaires’ disease and forms part of the Legionellosis, a collection of infections that emerged in the second half of the 20th century.

Legionellosis is affected by Legionella pneumophila and related bacteria and the severity of Legionellosis varies from mild febrile illness (Pontiac fever) to a potentially fatal form of pneumonia (Legionnaires’ disease). The disease infection can affect everybody, but principally affects those who are vulnerable due to age, illness, immunosuppression and other risk factors, such as smoking.

The name 'Legionella pneumophila' was given to a type of bacteria that causes Legionnaires' disease after an outbreak of an unknown illness occurred among people attending an American Legion convention in 1976. The outbreak caused 221 people to become infected and resulted in the tragic loss of 34 lives.

* “Legionella – World Health Organization.” https://www.who.int/publications/i/item/9241562978

Where does Legionella occur?

The Legionella is a harmful bacterium that occurs naturally in water (including freshwater environments like lakes and streams) and thrives in cold or hot water systems, which means its growth is generally found in piping in large buildings such as hospitals, hotels, and apartments. There are a range of external elements that can lead to a Legionella infection in your building, these include but are not limited to the following: 

·            Biofilm 

·      Changes in Water Pressure

·      Changes in Municipal Water Quality

·      Construction

·      Inadequate Concentrations of Disinfectant

·      pH Fluctuations and Variations 

·      Scale and Sediment

·      Water Main Breaks

·      Water Temperature fluctuations

·      Water Stagnation

In water systems, legionella tends to prosper in suboptimal temperature conditions. For cold water systems, it is recommended to maintain a specific cool temperature range, while for hot water systems, it is essential to ensure that the water temperature does not drop below a certain threshold. Essentially, legionella grows and spreads in lukewarm water.

 *”Legionella Growth and Spread | Healthcare Facilities | CDC.” https://www.cdc.gov/legionella/wmp/overview/growth-and-spread.html

How is Legionella spread? 

Legionella in water is spread by inhalation of small particles of contaminated and polluted water from sources such as air-conditioning systems, cooling towers, and hot-water tanks. Legionella pneumophila, the aetiological agent of 90% Legionellosis cases, is a common inhabitant of natural and anthropogenic freshwater environments, where it resides in biofilms. Where conditions encouraging, the bacteria may grow and increase the risk of Legionnaires’ disease therefore it’s essential that we act to control the risk and take preventative methods. 

Legionella can be transmitted across many parts of a building’s water system where the area is constantly wet or damp. Legionella can also transmitted through contaminated water droplets which are expelled through the environment by a device such as water filters, water valves and water storage tanks. 

*”Biofilms: The environmental playground of Legionella pneumophila https://www.researchgate.net/publication/26740150_Biofilms_The_environmental_playground_of_Legionella_pneumophila

How do you catch Legionella?

Legionella lives in freshwater and seldom causes illness.  However, in man-made settings, such as extensive pipework, Legionella, can develop if the water is not appropriately sustained Legionnaires’ diseases is contracted by inhaling droplets of water, suspended in the air, that contain the bacteria.  The most likely sources of infection include:

·      Cooling Towers (parts of large air conditioning systems)

·      Decorative Fountains

·      Hot Bath Tubs 

·      Water used for showering

*”Legionnaires’ Disease.” https://www.cdc.gov/legionella/downloads/fs-legionnaires.pdf. 

 Who is prone to the risk?

·      Individuals over 45 years of age (the risk rises with age)

·      Smokers or heavy drinkers

·      Individuals suffering from chronic respiratory diseases

·      Individuals suffering from kidney disease

·      Individuals suffering from diabetes, lung and heart disease

·      Anybody with an impaired immune system

*”What is Legionnaires’ disease? – HSE.”  https://www.hse.gov.uk/legionnaires/what-is.htm.

 *”Active Bacterial Core Surveillance for Legionellosis — United ….”  https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6442a2.htm.

 *”Legionnaires Disease, Pontiac Fever Fast Facts | CDC.” https://www.cdc.gov/legionella/fastfacts.html. 

Legionnaires’ Disease Fatality rate

According to data from the Center for Disease Control and Prevention (CDC), it has been observed that approximately 10% of people who contract Legionnaires' disease succumb to it, making it a fatal illness. If individuals are diagnosed with Legionnaires' disease early and treated with the appropriate antibiotics, their chances of recovery are higher than those who go undiagnosed for a longer period of time. Unfortunately, only a small proportion of Legionnaires' disease cases are identified, and many patients are misdiagnosed.

*”Legionnaires’ Disease | VitalSigns | CDC – Centers for ….” https://www.cdc.gov/vitalsigns/legionnaires/index.html 

Where can Legionella grow and spread?

Legionella has the ability to propagate in various sections of a building's water system that are persistently wet or moist. It can also extend through polluted water droplets that are released into the air by equipment like water filters, valves, and storage tanks.

Can Legionella be prevented? 

Yes, to prevent the outbreak of Legionella, you will need a long-term supplemental disinfectant added to your water.  Examples of such disinfectants include chlorine, mono-chlorine, chlorine dioxide, ultraviolet light and ozone.  

Although everybody understands the essential of controlling the existence of Legionella and other waterborne bacteria in engineered water systems, using potentially hazardous chemicals to do so could generate more harm than it solves. But there is another solution that produces ‘no compromise’ disinfection but is non-toxic and safer for both users and the environment – the GENOX Generator System from DCW, powered by  NEUTHOX®. 

*“Can Legionnaires Disease be Prevented? | HC Info.”  https://hcinfo.com/about/legionnaires-disease/what-precautions-can-be-taken/.

* “Legionella Growth and Spread | Healthcare Facilities | CDC.”  https://www.cdc.gov/legionella/wmp/overview/growth-and-spread.html.