Legionnaires’ Disease

Legionnaires’ disease is a type of pneumonia (lung infection) you get from breathing in Legionella bacteria. It can affect your lungs, brain and gut (gastrointestinal tract).

Many people with Legionnaires’ (LEE-juh-nares) disease get severely ill and need to be treated in the hospital. You might have long-term health problems, even after recovering from the infection.

Legionnaire’s disease is uncommon. Around 10,000 people in the U.S. are diagnosed with it every year.

Legionella also causes Pontiac fever, a less serious illness with flu-like symptoms. Legionnaires’ disease can be life-threatening.

Symptoms of Legionnaires’ disease

Symptoms start two to 14 days after exposure to Legionella. They include:

• Fever (often over 104⁰F/40⁰C)
• Cough (usually dry)
• Shortness of breath
• Diarrhea
• Muscle aches
• Headache
• Nausea
• Confusion
• Coughing up blood
• Belly (abdominal) pain

Legionnaire’s disease causes

Legionella bacteria cause Legionnaires’ disease. There are at least 60 species of Legionella. Legionnaires’ disease is most often caused by Legionella pneumophila. You get Legionnaires’ disease when the bacteria infect your lungs.

Legionella is found naturally in lakes, streams and soil, but it can also contaminate drinking water and air systems, especially in large buildings.

How do you get Legionnaires’ disease?

You can get Legionnaires’ disease by breathing in mist (aerosolized water) contaminated with bacteria. Water in your mouth can also get into your lungs accidentally, for instance, if it goes “down the wrong pipe” (aspiration). This can happen from:

• Hot tubs
• Shower heads
• Faucets
• Humidifiers
• Decorative water features, like fountains
• Heating and cooling systems (usually only in large buildings)
• Intubation during surgery
• Dirt (soil)

Swallowing water doesn’t infect you. You also can’t get it from another person (it’s not contagious).

Outbreaks of Legionnaires’ disease have happened in hotels, hospitals, long-term care facilities and cruise ships. But most cases aren’t part of outbreaks.

Risk factors

Most people don’t get Legionnaires’ disease, even if they’ve been around the bacteria. But some people are more likely to get sick than others. You might be at an increased risk of getting Legionnaires’ disease if you:

• Are older than 50
• Smoke or used to smoke cigarettes
• Have a weakened immune system
• Have a long-term respiratory illness, like COPD (chronic obstructive pulmonary disease)
• Live in a long-term care facility
• Have stayed in a hospital recently
• Have had surgery requiring anesthesia recently
• Are an organ transplant recipient

Complications

Legionnaires’ disease can have life-threatening complications. They include:

• Respiratory failure
• Acute kidney injury (AKI or acute renal failure)
• Encephalopathy, like confusion, balance problems and trouble talking
• Inflammation in or around your heart (myocarditis, pericarditis or endocarditis)
• Rhabdomyolysis

How doctors diagnose Legionnaires’ disease

Your healthcare provider will ask you about your health history and any recent travel. If they think you might have Legionnaire’s disease, they’ll use urine (pee) and sputum (mucus or phlegm) tests to confirm a diagnosis. They may also get pictures of the inside of your chest with an X-ray or CT scan.

Other tests or procedures could include:

• Blood tests: A lab will look for signs of Legionella in a sample of your blood. They can also use blood tests to understand how well your organs are working.
• Bronchoscopy: Your provider may use a thin, lighted tube to look at the inside of your lungs. They’ll take samples to be tested for signs of Legionella.
• Thoracentesis: You may need to have fluid drained from the outside of your lungs (thoracentesis). Your provider will test this fluid for signs of Legionella.

How is Legionnaires’ disease treated?

Healthcare providers treat Legionnaires’ disease with antibiotics. You may get antibiotics through your veins (IV) or in a pill that you swallow. These could include:

• Azithromycin
• Levofloxacin, moxifloxacin or ciprofloxacin
• Tetracycline, doxycycline or minocycline
• Rifampin

If you’re having trouble breathing, you may get treatments to help you get enough oxygen. You’ll probably have to stay in the hospital while you’re treated. In serious cases, you may need to have a machine breathe for you until you can do it on your own again.

When should I see my healthcare provider?

If you have symptoms of Legionnaires’ disease, contact your healthcare provider right away. If there’s an outbreak in a building where you’ve worked or stayed, ask your provider what precautions you should take.

Go to the emergency room if you:

• Have a high fever
• Are struggling to breathe
• Are coughing up blood
• Have any neurological symptoms (like balance issues, speech problems or confusion)

What can I expect if I have Legionnaires’ disease?

Legionnaires’ disease can make you very sick. It can also cause long-term health issues. Many people need treatment in the hospital. After you go home from the hospital, you may still need to take medications to make sure the infection goes away completely.

For several months afterwards, you may still have:

• Fatigue
• Problems with balance or coordination
• Trouble walking
• Slurred speech
• Muscle aches

Talk to your healthcare provider if you have concerns about ongoing symptoms.

Can you survive Legionnaires’ disease?

Legionnaires’ disease is very serious, but most people survive with treatment. It’s fatal in about 1 in 10 people who are treated. If left untreated or if treatment is delayed, it’s more likely to be fatal.

Can it be prevented?

Building managers can reduce the risk of Legionnaires’ disease by maintaining and properly disinfecting water and ventilation systems.

You can reduce your risk at home by making sure shower heads, faucets, hot tubs and humidifiers are properly cleaned and run regularly. Don’t use plain water in place of windshield wiper fluid in your car. The bacteria can grow in the water.