Legionella

To understand how DCW units 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

What is Legionella?

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 caused 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 can affect anyone, but principally affects those who are susceptible due to age, illness, immunosuppression and other risk factors, such as smoking.

The bacteria which causes Legionnaires’ disease got its name from an incident in 1976 where an outbreak of an unknown disease (assumed to be pneumonia) amongst people attending a convention of the American Legion infected 221 people and killed 34. Later the bacteria was named ‘Legionella pneumophila’.

* “legionella – World Health Organization.” https://www.who.int/water_sanitation_health/emerging/legionella.pdf. Accessed 30 Mar. 2020.

* “Bacterial control in water – Danish Clean Water.” https://www.danishcleanwater.com/Admin/Public/Download.aspx?file=Files%2FFiles%2FPDF%2F150122+General+brochure.pdf. Accessed 30 Mar. 2020.

Where does it occur?

The harmful bacteria Legionella occurs naturally in water (including freshwater environments like lakes and streams) and thrives in hot water, which means its growth is commonly found in piping in large buildings including hospitals, hotels, and apartment blocks. There are a variety of external factors that can lead to a Legionella infection in your building, these include (but are not limited to) the following:

  • Construction
  • Water main breaks
  • Changes in municipal water quality
  • Biofilm
  • Scale and sediment
  • Water temperature fluctuations
  • pH fluctuations
  • Inadequate levels of disinfectant
  • Changes in water pressure
  • Water stagnation

 *”Legionella Growth and Spread | Healthcare Facilities | CDC.” https://www.cdc.gov/legionella/wmp/overview/growth-and-spread.html. Accessed 30 Mar. 2020.

Where does it occur?

The harmful bacteria Legionella occurs naturally in water (including freshwater environments like lakes and streams) and thrives in hot water, which means its growth is commonly found in piping in large buildings including hospitals, hotels, and apartment blocks. There are a variety of external factors that can lead to a Legionella infection in your building, these include (but are not limited to) the following:

  • Construction
  • Water main breaks
  • Changes in municipal water quality
  • Biofilm
  • Scale and sediment
  • Water temperature fluctuations
  • pH fluctuations
  • Inadequate levels of disinfectant
  • Changes in water pressure
  • Water stagnation

 *”Legionella Growth and Spread | Healthcare Facilities | CDC.” https://www.cdc.gov/legionella/wmp/overview/growth-and-spread.html. Accessed 30 Mar. 2020.

How is Legionella transmitted?

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

 *”Biofilms: The environmental playground of Legionella ….” 28 Oct. 2019, https://www.researchgate.net/publication/26740150_Biofilms_The_environmental_playground_of_Legio

How do you catch it?

In nature, Legionella lives in freshwater and rarely causes illness. However, in man-made settings, such as extensive pipe-work, Legionella can grow if the water is not properly maintained Legionnaires’ disease is contracted by inhaling droplets of water, suspended in the air, that contain the bacteria. The most likely sources of infection include:

  • Water used for showering (potable water)
  • Cooling towers (parts of large air conditioning systems)
  • Decorative fountains
  • Hot tubs

 *”Legionnaires’ Disease.” https://www.cdc.gov/legionella/downloads/fs-legionnaires.pdf. Accessed 30 Mar. 2020.

How do you catch it?

In nature, Legionella lives in freshwater and rarely causes illness. However, in man-made settings, such as extensive pipe-work, Legionella can grow if the water is not properly maintained Legionnaires’ disease is contracted by inhaling droplets of water, suspended in the air, that contain the bacteria. The most likely sources of infection include:

  • Water used for showering (potable water)
  • Cooling towers (parts of large air conditioning systems)
  • Decorative fountains
  • Hot tubs

 *”Legionnaires’ Disease.” https://www.cdc.gov/legionella/downloads/fs-legionnaires.pdf. Accessed 30 Mar. 2020.

Who is at risk?

The bacteria’s worst form is known as Legionnaires’ disease and this poses a real threat to society, particularly to the elderly and those with compromised immune systems, though anyone can catch it. People at a higher risk of catching and not recovering well from Legionnaires’ disease include the following:

  • People over 45 years of age (the risk increases with age)
  • Smokers and heavy drinkers
  • People suffering from chronic respiratory diseases
  • People suffering from kidney disease
  • People suffering from diabetes, lung and heart disease
  • Anyone with an impaired immune system

Due to patients with pre-existing illnesses having a higher risk of catching Legionella, preventative measures against the bacteria have a high priority in hospitals, retirement and nursing homes, and other such institutions. At present, around one in ten people who contract Legionnaires’ disease will die, however, it’s believed that people are not capable of spreading the disease from person to person, though this could be possible under rare circumstances.

 *”What is Legionnaires’ disease? – HSE.” 12 Aug. 2014, https://www.hse.gov.uk/legionnaires/what-is.htm. Accessed 30 Mar. 2020.

 *”Active Bacterial Core Surveillance for Legionellosis — United ….” 30 Oct. 2015, https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6442a2.htm. Accessed 30 Mar. 2020.

 *”Legionnaires Disease, Pontiac Fever Fast Facts | CDC.” https://www.cdc.gov/legionella/fastfacts.html. Accessed 30 Mar. 2020.

Legionnaires’ Disease Fatality rate

The Center for Disease Control and Prevention (CDC) has produced data that indicates Legionnaires’ disease is deadly for around 10% of people who contract it. People who are diagnosed sooner and are treated with the correct antibiotics have a higher chance of recovering than those who are left undiagnosed for longer. However, only a small percentage of Legionnaires’ disease cases are detected, with many patients receiving an incorrect diagnosis.

*”Legionnaires’ Disease | VitalSigns | CDC – Centers for ….” 7 Jun. 2016, https://www.cdc.gov/vitalsigns/legionnaires/index.html. Accessed 30 Mar. 2020.

Is there a current Legionella threat?
Legionella continues to present a very real threat. In 2017, the EU/EEA reported the highest ever observed figures, an increase of 30% in the number of reported cases compared with 2016. The public health implications remain serious – Legionnaires’ disease is an important cause of potentially preventable morbidity and mortality in Europe and there is no indication of decreasing burden. In critical sites, such as hospitals and care homes, patients are particularly susceptible to contracting Legionella and concern around the issue is high, with outbreaks being reported with disturbing regularity.

Where can Legionella
grow and spread?

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

Can Legionnaires’ disease be prevented?
Yes, Legionnaires’ disease can be prevented as it’s considered to be an environmental disease as opposed to a communicable disease and when it comes to tackling Legionella outbreaks, prevention is truly the key. To reduce the incidence of Legionella building owners must carefully manage plumbing systems in a number of ways.

*”Can Legionnaires Disease be Prevented? | HC Info.” https://hcinfo.com/about/legionnaires-disease/what-precautions-can-be-taken/. Accessed 30 Mar. 2020.

* “Legionella Growth and Spread | Healthcare Facilities | CDC.” https://www.cdc.gov/legionella/wmp/overview/growth-and-spread.html. Accessed 30 Mar. 2020.

Ensuring your levels of disinfection are correct is vital when aiming to prevent a Legionella outbreak and you’ll likely need a long-term supplemental disinfectant added to your water to help limit Legionella growth. Examples of such disinfectants include chlorine, mono-chlorine, chlorine dioxide, ultraviolet light, and ozone.

While everyone understands the importance of controlling the presence of Legionella and other waterborne bacteria in engineered water systems, using potentially dangerous chemicals to do so could create more problems than it solves. But there is an alternative, a solution that delivers ‘no compromise’ disinfection but is non-toxic and safer for both users and the environment – the GENOX Generator System from DCW, powered by NEUTHOX®.

Legionella European Law

Under directive 2000/54/EC of the European Parliament and the Council (regarding the protection of workers from risks related to exposure of biological agents at work) employers are required to carry out risk assessments and take adequate measures to protect workers from Legionnaires’ disease. As a person who is responsible for water systems, you also have certain duties under the law to uphold the quality of the water and to manage it responsibly. As NEUTHOX® complies with ECHA regulations and has been approved by the Drinking Water Inspectorate (and cited in HSG274 Part 2), it’s one of the most effective measures of preventing Legionella growth on the market.

*Legionella and Legionnaires’ disease: a policy … – Eu-OSHA.” 28 Aug. 2011, https://osha.europa.eu/en/publications/legionella-and-legionnaires-disease-policy-overview/view. Accessed 30 Mar. 2020.

 *”What is Legionella? – Water Environmental Treatment … – WET.” http://www.wet-services.com/legionella.php. Accessed 30 Mar. 2020.

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Legionella European Law

Under directive 2000/54/EC of the European Parliament and the Council (regarding the protection of workers from risks related to exposure of biological agents at work) employers are required to carry out risk assessments and take adequate measures to protect workers from Legionnaires’ disease. As a person who is responsible for water systems, you also have certain duties under the law to uphold the quality of the water and to manage it responsibly. As NEUTHOX® complies with ECHA regulations and has been approved by the Drinking Water Inspectorate (and cited in HSG274 Part 2), it’s one of the most effective measures of preventing Legionella growth on the market.

View or download documents: