What is Legionnaires’ disease? Get the facts in under 30 seconds

We’ve created this useful Infographic titled “What is Legionnaires’ disease” to help people quickly understand more about this preventable disease, what it is, where it comes from, who’s at risk, typical symptoms, how it’s treated, common sources of risk in the workplace and the legionella risk assessment process.

What is Legionnaires disease infographic

What is Legionnaires' disease?

Legionnaires’ disease is a severe form of pneumonia caused by legionella bacteria. People catch it by breathing in tiny droplets of water (an aerosol) contaminated with legionella.

How did it get its name?

Legionnaires’ disease was named after members of the American Legion who caught the disease in 1976 during a convention in Philadelphia, USA. The bacterium that caused the illness was named Legionella pneumophila. Cases involving the disease have since been identified as far back as 1947 with others probably occurring before then.

Where is legionella bacteria found?

Legionella bacteria exist in the environment – including most nutrient-rich fresh waters including rivers and streams.

The bacteria can colonise man-made water systems including hot and cold water systems, cooling towers, types of air-conditioning, spa pools and decorative water features – in fact anything that creates an aerosol poses a risk.

Who is at risk from the disease?

Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection. There are other known risk factors that include the following:

  • people over 45 years
  • heavy drinkers
  • heavy smokers
  • people with underlying health conditions or an impaired immune system
  • people suffering from chronic respiratory or kidney disease
  • people suffering with diabetes, lung and heart disease

How is Legionnaires’ spread?

Legionnaires’ is not a contagious disease and cannot be transmitted person to person. Typically, people get it by breathing in a contaminated aerosol (small droplets of water) containing legionella bacteria - as it enters the lungs the bacteria grow causing Legionnaires’ disease or Pontiac fever.

In the UK

In 2015, 382 people in England and Wales caught the disease - nearly half of them catching it abroad.

In the USA

Currently around 5,000 people are hospitalised in the USA every year, although it is suspected that the figure is probably higher – this is because many cases are not diagnosed correctly or simply not reported.

Symptoms of Legionnaires' disease

Legionnaires’ disease is a severe form of pneumonia. The first symptoms usually appear 2 to 10 days after infection. Early symptoms are similar to those of flu and can include:

  • fever and chills
  • a dry cough
  • muscle aches and pains
  • headaches

Treatment of Legionnaires' disease     

If you contract Legionnaires’ disease it can usually be treated with antibiotics.

Are there Legionella risks in your workplace?

Legionnaires' disease is considered to be preventable, however given the correct environmental conditions, any man-made water system may allow legionella bacteria to grow. Legionella risks are increased if your water system:

  • has a water temperature between 20 °C and 45 °C
  • creates or spreads breathable droplets of water, e.g. aerosol created by a cooling tower or shower
  • stores or re-circulates water
  • contains nutruents for the bacteria to grow – this can include rust, scale, organic matter and biofilm

What are the most common sources of risk?

The most common sources of legionella in man-made water systems include:

  • cooling towers and evaporative condensers
  • hot and cold water systems
  • spa pools

What do you need to do to manage the risks?

The first step in managing the risks from Legionella bacteria and the resulting Legionnaires’ disease is to assess the risks your water systems create for you, your colleagues and those people around you. You should do this by carrying-out a Legionella Risk Assessment.

Further information, support and advice

If you have questions about any of the issues raised above or you would like to speak with one of our specialists please call us today on 0161 877 0586 or contact us here.

Get in touch...

Legionella Control International
Unit B Badex Building
Westbrook Park
Manchester M17 1AY
United Kingdom

Manchester: +44 (0) 161 877 05 86
London: +44 (0) 203 637 47 48
Email: info@legionellacontrol.com

Download our latest brochure...

Legionella Control & Water Safety Services Brochure 

Eliminate uncertainty, mitigate your risk now…

Contact Us Today

Legionella Control International is trusted by clients worldwide...