Legionnaires Disease

Overview

Legionnaires' disease is a serious type of pneumonia, or lung infection. It is caused by bacteria called Legionella. You get it by breathing in tiny droplets of water that contain the bacteria. It is not spread from person to person.

It is uncommon. In the UK, only a few hundred cases are reported each year. However, it can cause serious illness, especially in older adults and people with other health conditions.

Anyone can get Legionnaires' disease, but it is most common in people over 50, smokers, and those with weakened immune systems or long-term lung conditions.

Symptoms

Common symptoms

• A cough that may bring up phlegm
• High temperature (fever)
• Chills
• Muscle aches
• Headache
• Shortness of breath
• Chest pain

Symptoms in children

• Fever
• Cough with rapid breathing
• Feeling very tired
• Poor feeding or low energy

Symptoms in older adults

• Confusion or changes in mental state
• Cough and shortness of breath
• High fever, or sometimes a lower-than-normal temperature
• Weakness and drowsiness

Causes

Main causes

• Breathing in contaminated water droplets from air conditioning systems, cooling towers, hot tubs, showers, or decorative fountains.
• Choking on contaminated water into the lungs, which can happen in people with swallowing problems or during a hospital stay.

Risk factors

• Being over 50
• Smoking or using e-cigarettes
• Chronic lung disease (like COPD or asthma)
• Weakened immune system due to illness or medicines
• Recent surgery, especially a transplant
• Diabetes, kidney disease, or heart disease
• Heavy alcohol use

When to see a doctor

See a doctor urgently if:

• You have a cough and shortness of breath
• You have a high fever with chest pain
• You feel confused or are finding it hard to stay awake

Book a routine appointment if:

• You have a new cough with fever and flu-like symptoms
• You feel unwell, especially after being in a hot tub or using a shower or air conditioner that might not be well maintained

Diagnosis

Your doctor will ask about your symptoms, recent travel, and whether you have been around any water systems that might be contaminated. They will listen to your chest and, if they suspect Legionnaires' disease, they will arrange tests.

Tests that may be done

• Chest X-ray
• Urine test to look for Legionella bacteria
• Phlegm (sputum) culture
• Blood tests

What to expect at your appointment

You may need to give a urine sample and have blood taken. A chest X-ray is quick and painless. It can take a few days for culture results to come back, so doctors often start treatment based on your symptoms and test results.

Treatment

Legionnaires' disease is treated with antibiotics. Many people need to be cared for in hospital, especially if breathing is difficult or there are other health concerns. Starting treatment early greatly improves recovery.

Self-care at home

• Rest as much as possible
• Drink plenty of fluids to stay hydrated
• Take your medicines exactly as prescribed
• Avoid smoking and secondhand smoke
• Ask your healthcare provider before taking any medicines for fever

Medical treatments

Antibiotics are the main treatment. They may be given by mouth or through a drip, depending on how severe the infection is. You may also receive oxygen therapy, fluids through a drip, and supportive care to help you breathe. In more severe cases, a hospital may provide breathing support using a ventilator, but many people do not need this.

Living with this condition

Recovery can take several weeks or even months. You may feel tired and short of energy. It is important to ease back into normal activities slowly and follow your doctor's advice.

Lifestyle tips

• Avoid smoking and be around others who smoke
• Take all of your prescribed medicine, even if you start to feel better
• Go to your follow-up appointments
• Get plenty of rest and sleep

Diet and exercise

Eat a balanced diet with enough protein and calories to help your body heal. Light exercise, such as short walks, can gradually help you regain strength, but only start when your doctor says it is safe.

Mental health and emotional wellbeing

Being seriously ill can be stressful and frightening. It is normal to feel low, anxious, or weak during recovery. Talk to your healthcare team about how you are feeling, and accept support from family and friends.

Prevention

Yes, in many cases. Legionnaires' disease is prevented by making sure water systems are properly cleaned, maintained, and monitored. This includes cooling towers, hot tubs, shower heads, tap aerators, and air conditioning units.

Vaccines

There is no vaccine for Legionnaires' disease. Prevention relies on safe water systems and good maintenance, especially in hospitals, hotels, and public buildings.

Screening programmes

There is no routine screening test for Legionnaires' disease in the general public. If you are at higher risk, it is especially important to avoid poorly maintained water systems and to follow safe water practices when travelling or using facilities like spas.

Complications

If left untreated

• Respiratory failure, when the lungs cannot supply enough oxygen to the blood
• Septic shock, a dangerous drop in blood pressure that damages organs
• Kidney failure
• Lung abscess, a collection of pus in the lung

Long-term outlook

With prompt treatment, most people recover from Legionnaires' disease. Full recovery can take time, and some people feel tired for weeks or months. Early treatment greatly reduces the risk of serious complications, so seeking medical help quickly is the best thing you can do.

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