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    Legionella Disease

    Legionella and Legionnaires Disease

    Published on October 25th, 2022 | by Sophie West

    Public Health England state that the water-borne illness; Legionnaires disease, is fatal in around 10% of cases. So, what is it and how is it caused?

    What is Legionella?

    Legionella is a group of bacteria found in both natural and man-made water systems. Whilst common in rivers, lakes and reservoirs, it’s usually in low numbers and moving freely, and therefore very low risk.

    Legionella can contaminate purpose-built water systems such as cooling towers, evaporative condensers, hot and cold water systems in buildings and whirlpool spas. The bacteria attach to solid surfaces and multiply where temperatures are between 20-45°C and they have a nutrient supply, so it is imperative these systems are well designed and adequately maintained or the risk to human health is high.

    What is Legionnaires disease?

    Legionellosis is the collective name given to the pneumonia-like illness caused by Legionella bacteria. This includes the most serious; Legionnaires’ disease. Symptoms can take between 2-10 days to develop and include:

    • Fever
    • Tiredness
    • Nausea
    • Diarrhoea
    • Coughing
    • Breathlessness

    Legionnaires disease causes infection by being inhaled deep into the lungs through aerosols; fine mist from water droplets. It’s not the water itself that causes the infection, but what is left after the water evaporates.

    Due to the similarity of the disease to other respiratory conditions, it can go easily undiagnosed.

    Who is susceptible to Legionnaires disease?

    It is most common in adults over 45 years (typically older men), smokers, heavy drinkers, sufferers of heart, lung or kidney disease, and those with low immune systems.

    How can risks be minimised?

    Keeping water clean and flowing helps to control the risks of Legionella, and it is essential that regular maintenance is carried out on water systems including cleaning and system checks.

    Who is responsible for ensuring risks are minimised?

    The Health and Safety at Work etc Act 1974 enforces the control of Legionella in the UK, and under general health and safety law, as an employer or person in control of a premises (e.g. a landlord), you must to take suitable precautions to prevent or control the risk of exposure to Legionella.

    How can Agility Risk and Compliance help?

    Here at Agility, we offer a number of options from our half day Legionella Awareness training course to Legionella surveys and  risk assessments. If you’d like more information or some guidance on what would suit your business then give our friendly team a call on 01527 571 611.

    Source: HSE –

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