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Last updated: 25.08.17

Legionella and Legionnaires’ Disease Symptoms

In this article, we’re going to take a look at one of the rarer forms of pneumonia encountered in the UK; Legionnaire’s disease, and the bacteria (Legionella) that causes it. We’ll cover how it can be contracted, how it can be identified, how it can be prevented, and how it can be treated.

Virtual College offers a specific Legionnaires’ awareness course that’s designed to help businesses understand how the risk of the disease can be mitigated, and the legislation relevant to this. Click here to find out more about what this course entails.

What is Legionella and What is Legionnaires’ Disease?

Legionella is a form of bacteria (Legionella pneumophila), which causes the Legionnaires’ disease. The two phrases are often confused, but are distinct in their meaning. This bacteria is one that lives primarily in freshwater, but can also be found in soils and other environments. It is fairly common, but is not usually a risk, and exposure does not usually cause the contraction of the associated disease.

Legionnaires’ disease is a type of pneumonia, but due to the nature of Legionella, it accounts for less than 10% of pneumonia cases, and outbreaks are even rarer. It does sometimes require hospitalisation however, and there is a small but significant mortality rate, almost exclusively in at-risk groups. The name of the disease comes from the first recorded outbreak, which occurred at the 1976 American Legion convention in Philadelphia.

How is Legionella Contracted and How Can it Be Prevented?

Legionnaires’ disease is usually contracted when a person breathes in water droplets that are contaminated with Legionella bacteria. In turn, the bacteria in this water infects the lungs, which is what causes the pneumonia. This most frequently happens in buildings where the water supply system has become contaminated with the bacteria. Due to the large and complex water system in many buildings, the bacteria can spread quickly. As with the first recorded outbreak, hotels, offices and other similar establishments are most at risk.

It’s important to note that Legionnaires’ disease is not known to be able to be spread from person to person.

Prevention of Legionella is fairly straightforward, and most modern buildings will carry no risk of having their water supplies contaminated with it. The bacteria thrive in warmer water of 20-45 degrees celsius, and generally requires impurities such as algae and limescale to feed on. Provided water supplies are kept below or above 20-45 degrees celsius, they are not stagnant, and they are kept clean or periodically cleaned, Legionella can be prevented. Legionella testing is not common, but can be carried out to check water quality and safety.

If you are in any doubt as to how you can prevent Legionella from contaminating your organisation’s water supply, then our Legionnaires’ awareness course can help.

What are the Symptoms of Legionnaires Disease?

Symptoms of Legionnaires’ disease include the following, which are also frequently symptoms of other forms of pneumonia:

  • Headaches
  • General body and muscle pain
  • Fever and/or chills
  • Confusion and tiredness
  • Chest pains
  • Difficult breathing
  • Persistent cough

If you suspect yourself or another person of Legionella as a result of the above, then you should seek a GP appointment as soon as you can. However, if you or the person experiences severe coughing, chest pain and difficulty breathing, then more urgent medical attention should be sought. Be aware that Legionnaires’ disease has an incubation period in which no symptoms will be displayed - this is usually around a week.

A GP will conduct a urine test to determine if a person has Legionnaires’ disease.

Who is Most at Risk?

As with all forms of pneumonia, certain groups are significantly more at risk from Legionnaires disease than others. They include the following:

  • Older people generally are more at risk of contracting the disease, with the vast majority of cases being aged over 50
  • Smoking can make a person’s lungs more susceptible to infection such as the Legionella bacteria
  • Pre-existing medical conditions such as lung disease can make infection more likely and also lead to complications
  • Those with weaker immune systems, such as people diagnosed with HIV, can be more susceptible to Legionnaires’ disease

At-risk groups are more likely to develop a more serious form of the disease, and may need increased medical attention.

How is Legionnaires Disease Treated?

Legionnaires disease is treated with a course of antibiotics. This usually lasts around a week, and in the vast majority of cases people will make a full recovery fairly quickly. In some cases, hospital admittance may be required, but this is thankfully rare, and further complications are only likely in those with pre-existing medical conditions.

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