What is Legionnaires disease

What is Legionnaires disease (Legionellosis)?

Legionnaires’ disease (Legionellosis) is a serious and sometimes fatal form of pneumonia caused by the bacteria Legionella.

Although not all cases of Legionnaires’ disease are severe, up to ten per cent of cases can be fatal.

There are over forty strains of Legionella bacteria but only a few cause disease in humans. The strains that are most commonly associated with human disease are pneumophila and longbeachae.

What are the symptoms of Legionnaires’ disease?
Symptoms are usually similar to a severe ‘flu’ infection and include fever, headache (often severe), shortness of breath, muscle aches and pains and sometimes a dry cough.

From the time of infection with Legionella bacteria, it takes between two and 10 days for symptoms to appear. In most cases, symptoms begin after five or six days.


How do you get Legionnaires’ disease?
Legionella bacteria are found naturally in the environment and thrive in warm water and warm damp places. They are commonly found in bodies of water, soil and potting mix.

People usually get Legionnaires’ disease by breathing in Legionella bacteria in very fine droplets of water called aerosols.

Man-made water systems sometimes provide environments that let Legionella bacteria increase to large numbers. These man-made systems include showers, spa pools, fountains, and also cooling towers associated with air conditioning and industrial cooling processes.

The evaporative units sometimes used in home air conditioning units have not been known to cause Legionnaires’ disease. You cannot catch Legionnaires’ disease from another person, or from drinking water contaminated by Legionella bacteria.


Who is at risk for Legionnaires’ disease?
Most people exposed to Legionella bacteria do not become infected. The risk of disease increases with age, especially amongst smokers. People with long term medical conditions that weaken the body’s immune system (such as cancer, lung disease, diabetes, and transplant recipients) may be at increased risk of Legionnaires’ disease.


How is the disease diagnosed?
For people who already have symptoms of the infection, there are three main tests for diagnosing Legionnaires’ disease. These are: sputum tests; blood tests (this takes 2 tests more than 4 weeks apart); and a urine test. There is no value in being tested unless you are ill.


Can it be treated?
Yes, most people with Legionnaires’ disease need to be treated in hospital and for some, this will be in an intensive care unit. Legionnaires’ disease is treated with antibiotics and the earlier that treatment is begun, the better the outcome.


Can Legionnaires’ disease be prevented?
There is no vaccine currently available for the prevention of Legionnaires’ disease, however, there are measures that will reduce the risk of transmission. Owners of premises that have cooling towers, public spa pools, or warm water systems (for example in hospitals) are required by law to conduct regular maintenance of this equipment to reduce the risk of Legionella contamination and spread.



Legionella Control Association

Water Hygiene Systems Ltd is a member of the Legionella Control Association (LCA), whose membership comprises of companies who provide products and services concerned with the control and management of legionella bacteria within water systems.
As a member of the LCA, we are registered to undertake the following: –
Risk assessment services
Water treatment services
Hot and cold water monitoring and inspection services
Cleaning and disinfection services
Independent consulting services
Training services
Legionella analytical services
Plant and equipment services
The membership is now over 300 organisations who have satisfied the registration requirements of the LCA and re-register annually. Membership is voluntary but is seen across the industry as increasingly important in demonstrating a commitment to high standards of service. Many public and private tenders for water system services now require bidders to be registered with the LCA.
To download a current copy of our LCA certificate and the LCA code of conduct,
Our LCA Certificate :
Registration No. 2011/1861


To download a code of conduct for service providers document,



Please contact us to discuss any requirements you may have in more detail on:

Tel: 01494 453 977 Email: info@waterhs.co.uk


Sampling & Assessment

We take samples of water and residue from damp areas where potential bacteria and bugs, especially Legionella may be found which could lead to public health / disease outbreaks.


Bacterial Analysis

We analyse all the samples in our laboratory and report on the findings in full detail of the current and potential areas of concern or affect your regulatory requirements.


Resolution & Certification

From the results, an action plan is produced which could be a one-off solution or a maintained operation to ensure high standards of water quality and health & safety regulations.

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