Legionnaires’ Disease

Pneumonia is a lung infection that can make it hard to breathe and cause high fever, coughing and chest pain. While there are many causes of pneumonia, one of the most serious forms is Legionnaires’ disease. This type of pneumonia is caused by bacteria and is not common. 

Learn more about Legionnaires’ disease, its symptoms and how to protect yourself.

What is Legionnaires’ disease?

Legionnaires’ disease is a type of pneumonia you get from Legionella bacteria. People usually get the bacteria by breathing in droplets of water or soil that contain the bacteria. 

Legionella can affect your lungs, brain and gut (gastrointestinal tract). It can also cause Pontiac fever, a less serious illness that causes flu-like symptoms. 

Legionnaires’ disease got its name from an outbreak in 1976. During a large American Legion convention, more than 200 attendees fell ill and 34 of them died from a mysterious form of pneumonia. Health officials eventually linked a previously unknown bacteria called Legionella pneumophila to the cause.

What causes Legionnaires’ disease?

Legionella bacteria are naturally found in lakes and streams. They thrive in warm water, such as spas, showers, fountains and even air conditioning units. If these places are not properly cleaned and maintained, the bacteria can grow and spread into the air in water droplets. 

Outbreaks of Legionnaires’ disease have been linked to:

• Drinking water
• Hot water tanks and heaters
• Swimming pools
• Hot tubs and whirlpools
• Birthing pools

The infection can also be spread from potting soil and by aspiration when liquids accidentally enter your lungs because you cough or choke while drinking. 

Legionnaires’ disease is not contagious and cannot be passed from person to person. 

Who is at risk for Legionnaires’ disease?

Most healthy people will not get sick from the bacteria. However, certain factors can increase your risk. These include:

• Age: People over the age of 50 are at higher risk.
• Smoking: Smoking damages your lungs and can make it easier for the bacteria to cause an infection.
• Weak immune system: People with weakened immune systems, like those with cancer or HIV/AIDS, are at greater risk.
• Chronic conditions: Conditions like COPD (chronic obstructive pulmonary disease) or diabetes can increase the risk of infection.
• Recent surgery or hospitalization: People recovering from surgery requiring anesthesia or who recently stayed in a hospital.   

How do I know if I have Legionnaires’ disease?

Legionnaires’ disease can resemble the flu or a regular pneumonia infection. However, it is more serious and requires immediate medical treatment. Symptoms may appear two to 10 days after exposure to the bacteria. 

Symptoms of Legionnaires’ disease may include:

• High fever (over 104°F/40°C)
• Cough (may produce mucus)
• Shortness of breath or problems breathing
• Muscle aches and pains
• Headache
• Chest pain
• Tiredness or fatigue
• Gastrointestinal symptoms, like diarrhea or nausea

Contact your health care provider right away if you are experiencing these symptoms. Call 911 or go to the nearest emergency department (ED) if you have a high fever, cough up blood, struggle to breathe or are experiencing confusion, balance or speech problems.

How is Legionnaires’ disease diagnosed?

If your health care provider thinks you might have Legionnaires’, they will ask you about your symptoms, recent travel history and any possible exposure to contaminated water. 

They may also perform tests to confirm the diagnosis, such as:

• A blood or urine test to check for signs of infection
• A chest X-ray to see if there is any lung damage
• A sputum culture to look for Legionella bacteria in a sample of mucus or phlegm

Treating Legionnaires’ disease

Legionnaires’ disease is treated with antibiotics. The earlier you start treatment, the better the chances of a full recovery. In some cases, people with the infection may need to stay in the hospital to receive antibiotics through an IV. Treatment may also include oxygen therapy to help your lungs get the oxygen they need. 

Complications of Legionnaires’ disease

Legionnaires’ disease is a serious illness that can have serious complications. About one out of 10 people who get sick with the infection will die due to complications from the illness.

Possible serious complications include:

• Respiratory failure
• Sepsis (infection spreads to the bloodstream)
• Kidney failure
• Encephalopathy (neurological symptoms)
• Acute respiratory distress syndrome (fluid builds in the lungs’ air sacs)
• Death

Early diagnosis and treatment with antibiotics can help avoid these complications. If you think you have Legionnaires’ disease, seek medical care immediately. Your health care provider or a Banner Health specialist can help prevent and manage complications effectively. 

How can I prevent Legionnaires’ disease?

Preventing Legionnaire’s disease is mainly about making sure that water systems are clean and well-maintained.

Here are some tips to reduce the risk of getting the disease:

• Keep water systems clean: Regularly clean hot tubs, air conditioners, humidifiers and cooling towers to help prevent the growth of Legionella bacteria.
• Check water temperatures: Legionella bacteria thrive in warm water, so it’s important to keep water temperatures below 120°F in showers and hot tubs.
• Proper maintenance of plumbing systems: Large buildings and hotels should regularly inspect and clean their plumbing and water systems to prevent bacterial growth.
• Stay away from possible sources: If you’re in an area with contaminated water, such as an old hotel or a poorly maintained pool or spa, avoid it if you are at higher risk for infection.

Get treatment

Legionnaires’ disease is a serious infection but with proper care it’s treatable. If you think you’ve been exposed or are showing symptoms, don’t wait. Get medical help right away. Banner Health is here to provide expert care and resources to help you stay healthy and recover quickly.