Legionnaires' Disease

What is Legionnaires' Disease?

From: MedlinePlus, National Library of Medicine

Legionnaires' disease is a serious type of pneumonia caused by Legionella bacteria. The disease got its name when a group of people at an American Legion convention became ill with this type of pneumonia.

Legionella is found naturally in freshwater, such as lakes and rivers. It can also be found in soil. But people usually only get sick from it when if it grows and spreads in man-made water systems. These systems can include hot tubs, fountains, and the plumbing systems of large buildings, such as hotels or nursing homes.

Legionella can also cause Pontiac fever. This is a milder, flu-like illness that doesn't infect your lungs.

What causes Legionnaires' disease?

From: MedlinePlus, National Library of Medicine

You usually can't get infected by drinking water that contains the bacteria unless you aspirate it (accidentally breathe the water into your lungs). The bacteria don't spread from person to person. Disease outbreaks happen when many people are exposed to the same water source that contains the bacteria.

Who is more likely to develop Legionnaires' disease?

From: MedlinePlus, National Library of Medicine

Most healthy people who come in contact with the bacteria do not become sick. You are more likely to develop an infection if you:

• Are over the age of 50
• Are a current or former smoker
• Have a chronic (long-lasting) disease such as diabetes or kidney failure
• Have a chronic lung disease such as COPD or emphysema
• Have a weakened immune system due to a disease such as HIV or cancer or are taking medicines that suppress your immune system
• Live in a long-term care facility
• Have recently stayed in a hospital or had surgery requiring anesthesia

What are the symptoms of Legionnaires' disease?

From: MedlinePlus, National Library of Medicine

The symptoms usually show up 2 to 14 days after you were exposed to Legionella bacteria. Most of the symptoms are similar to those of other types of pneumonia. But Legionnaires' disease may also cause gastrointestinal symptoms and mental changes.

The symptoms of Legionnaires' disease may include:

• Cough
• High fever
• Chills
• Headache
• Chest pain
• Shortness of breath
• Fatigue
• Nausea and vomiting
• Diarrhea
• Confusion

What other problems can Legionnaires' disease cause?

From: MedlinePlus, National Library of Medicine

Legionnaires' disease can cause life-threatening complications such as respiratory failure, kidney failure, and sepsis.

About 1 out of every 10 people who get sick with Legionnaires' disease will die from complications of the illness.

How is Legionnaires' disease diagnosed?

From: MedlinePlus, National Library of Medicine

To find out if you have Legionnaires' disease, your health care provider will probably order a chest x-ray to see if you have pneumonia. If you do have it, lab tests such as a urine or sputum test can check for the Legionella bacteria. Your provider may also order a blood test to see if you have been exposed to the bacteria.

What are the treatments for Legionnaires' disease?

From: MedlinePlus, National Library of Medicine

If you have Legionnaires' disease, you will likely need care in a hospital. The treatment is with antibiotics. Most people will recover, especially if they were healthy when they got the disease. Getting treatment early can increase the chances of getting better.

Can Legionnaires' disease be prevented?

From: MedlinePlus, National Library of Medicine

You can lower your risk of getting Legionnaires' disease if you:

• Clean all your water-related devices regularly. This could include portable humidifiers, water heaters, air conditioners, and nasal rinses.
• If you haven't used your faucets and showerheads for a week or more, flush them by letting the hot and cold faucets run for at least two minutes before use.
• Avoid exposure to water sources such as decorative foundations or hot tubs if you don't know how well they are maintained.
• Use windshield cleaner in your wiper fluid tank in your car instead of water.
• Ask about how well your buildings' water systems are maintained.

Which doctor should you see?

The suggested department for discussing Legionnaires' Disease is Infectious Diseases, with a general physician / infectious disease specialist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which exposure or organism is suspected, and what evidence would confirm it?
• Are precautions, vaccination or advice for close contacts relevant to this infection?
• What should happen if symptoms worsen or do not improve as expected?

Treatment discussions and follow-up

Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.