Symptoms and Treatment of Legionella and Legionnaires’ Disease

November 2, 2016
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What is Legionnaires’ Disease & Legionellosis?

Legionellosis is the collective name given to the pneumonia-like illness caused by legionella bacteria, including the most serious condition, Legionnaires’ disease. People can catch Legionnaires’ disease by inhaling small droplets of water, suspended in the air, containing the bacteria. On average there are 300-400 reported cases of the disease each year, yet the problem is probably much worse as many people do not report it.

Legionella bacteria are common in natural water sources such as rivers, lakes and reservoirs. However, they may also be found in purpose-built water systems, such as cooling towers, evaporative condensers and whirlpool spas. If conditions are favourable then the bacteria may grow, increasing the risk of Legionnaires’ disease.

Legionnaire's Disease Symptoms

COVID-19 and Legionella

Due to COVID-19, many premises have been closed and unoccupied for a long period of time, or have been much more empty than usual. This means that water supplies have been sitting unused and stagnant, creating conditions that are perfect for bacteria to thrive in. As a result, there is an increased risk of Legionella bacteria growing in water systems, and in turn an increased risk of those who use water supplies contracting Legionnaires’ disease.

If you are a duty holder, you must revisit your risk assessment for your water supplies and ensure that they are correctly treated and cleaned before your building reopens.

Need training for Legionella and carrying out a risk assessment? High Speed Training provides an online Legionella and Legionnaires’ Awareness Training course, which is designed for duty holders and contains a module dedicated to carrying out a Legionella risk assessment.


Legionella and Legionnaires’ Disease Symptoms

Legionella and Legionnaires’ disease symptoms are similar to those of flu, i.e. a high temperature, fever and chills, a cough, muscle pains and headache.

They both often begin with an initial phase, with symptoms such as:

  • Headaches.
  • Muscle pain.

This is followed by more severe symptoms, such as:

  • High temperatures.
  • Severe muscle pain.
  • Chills.
  • Tiredness.
  • Confusion.

If the bacteria affect your lungs then you may also suffer from a persistent cough, shortness of breath or chest pains.

Some people with Legionnaires’ disease also have symptoms affecting the digestive system, including diarrhoea, feeling or being sick and loss of appetite.

Legionnaires’ disease is not known to be contagious.

Legionnaire's Disease Treatment


Legionella and Legionnaires’ Disease Treatment

If you develop any of the symptoms above and you are worried that it might be Legionnaires’ disease, then you should see your GP as soon as possible. In particular, a high temperature is likely to indicate that you have an infection of some kind.

As Legionnaires’ disease is similar to flu, it is not always easy to diagnose: a blood or urine test is usually done to help decide whether an illness is or is not Legionnaires’ disease. Most patients with Legionnaires’ disease are then admitted to hospital.

Legionnaires’ disease is usually treated successfully with intravenous (IV) antibiotics – around 90% of people make a full recovery. The usual antibiotic to treat Legionnaires’ disease is erythromycin but others, such as azithromycin, clarithromycin, levofloxacin, ciprofloxacin or doxycycline, are often used. Treatment lasts between 1-3 weeks.

If the patient is having trouble breathing due the pneumonia-like symptoms of Legionnaires’ disease then they may be given oxygen to aid the lungs.

If you suspect that you may have got Legionnaires’ disease as a consequence of your work then you are advised to report this to your manager as well as your health and safety representative and occupational health department.


Further Resources on Legionella