Legionnaires' Disease Signs & Symptoms | Baptist Health (2024)

What Is Legionnaires’ Disease?

Legionnaire’s disease is a potentially dangerous form of pneumonia caused by a species of Legionella bacteria. The disease and its source derive their names from the first-identified outbreak, an American Legion convention in 1976, but it isn’t limited to persons of that or any other organization. Pontiac fever is a milder variant caused by the same bacteria. Legionnaire’s disease requires medical treatment, normally including hospitalization. If left untreated, it can be fatal.

If you or a loved one develops the symptoms of Legionnaire’s disease, seek medical care immediately. The Baptist Health pulmonology team is ready to serve you.

Signs & Symptoms

The symptoms of Legionnaire’s disease appear two to ten days after exposure and are typical of pneumonia. The first wave of symptoms includes:

• Achy muscles
• Headache
• High fever

These are followed by indicators of a lung infection:

• Chest pain
• Hard coughing sometimes producing mucus or blood
• Disorientation
• Labored breathing
• Nausea, vomiting, and bowel distress

Unlike Legionnaire’s disease, Pontiac fever doesn’t attack the lungs. Its symptoms are more typical of a flu (headache, fever, achiness). Pontiac fever is less likely to require hospitalization, and often clears up on its own in a few days.

Causes

Legionnaire’s disease is caused by a species of Legionella bacteria, most commonly Legionella pneumophilia. These bacteria are found in freshwater, where they are rarely a source of concern. More problematic is their infiltration of various human-made water-use systems in homes and commercial properties, including:

• Heating and cooling (HVAC) systems
• Faucets, shower heads, and other indoor plumbing fixtures
• Humidifiers and dehumidifiers
• Hot tubs
• Hot water tanks and heaters
• Cooling towers for large air-conditioning units
• Reservoirs holding windshield-wiper fluid in automobiles
• Fountains and exterior water features

Room-unit air conditioners are an exception to this list. They do not utilize water as part of their air-cooling technology. Legionella can also be found in any soil with moisture content, including the potting soil used by gardeners.

There are two primary means by which the disease is transmitted:

• Inhalation: Anyone coming in close contact with a human-built water system runs the risk of inhaling bacteria in the form of airborne droplets produced by the system’s operation.
• Aspiration: Legionella can also be ingested directly into the lungs when drinking or accidentally swallowing water in an aquatic environment.

Legionnaire’s disease is not spread by person-to-person contact.

Risk Factors

A person’s likelihood of developing Legionnaire’s disease varies considerably based on several factors. Young otherwise healthy persons are not usually susceptible. A number of conditions make it more likely that an individual will be affected:

• Age: Persons aged 50 years or older have a greater overall risk.
• Tobacco use: Smoking increases the possibility of contracting the disease.
• Chronic illness: Certain long-term chronic illnesses, such as diabetes, some cancers, emphysema, and chronic obstructive pulmonary disease (COPD), weaken the immune system and raise the potential danger of infection.
• Recent medical procedures: Individuals who were recently hospitalized, had surgery with anesthesia, or underwent an organ-transplant procedure are vulnerable to lung infections, including Legionnaire’s disease.
• Residence in a long-term care facility: Persons living in a nursing home, assisted-living facility, or other long-term care facility also have a greater chance of being exposed to this disease.

Diagnosis

A diagnosis of Legionnaire’s disease must first confirm the presence of a lung infection and then identify the specific cause (in this case, the Legionella bacteria). After your physician has documented your symptoms and conducted a physical exam, he or she will arrange for:

• Imaging scans: An image scan is a non-invasive picture of the organs in your chest cavity using an X-ray or computerized tomography (CT) machine. Your doctor will be able to see fluid buildup or other indicators of pulmonary congestion.
• Bronchoscopy: In some cases, your physician may insert a thin, lighted tube with a tiny camera into your lungs through the nose. This will allow him or her to look inside your airways and to gather a small sample of tissue for analysis in a lab.
• Tests: Legionella bacteria often spread from the lungs into other parts of the body. By collecting urine, sputum (spit), and/or blood samples for analysis, your physician can confirm the role played by this pathogen in your pneumonia.
• Thoracentesis: In more severe cases, your physician may order thoracentesis, an invasive procedure for draining fluid from the lungs.

Treatment Options

Legionnaire’s disease doesn’t just “go away”. It requires sustained medical attention, typically in a hospital. It is treated with antibiotics, often administered intravenously. Patients having trouble breathing may also receive oxygen until their lung capacity improves.

With proper treatment, most persons suffering from Legionnaire’s disease eventually recover. Expect to continue with antibiotics for some time, even after release from the hospital. You may experience mild, flu-like symptoms during your recovery period, including achiness, slurred speech, fatigue, and reduced muscle coordination.

If not addressed, Legionnaire’s disease can have severe complications, up to and including death. These include respiratory failure, kidney injury, neurological problems, cardiac inflammation, and a form of muscle-tissue breakdown called rhabdomyolysis.

Prevention

The primary means of preventing Legionnaire’s disease is to stop the buildup of Legionella bacteria in home and commercial water-use systems. Regular maintenance is typically required. The Centers for Disease Control and Prevention (CDC) and other agencies offer guidelines for the control of waterborne germs, including those that cause Legionnaire’s disease.

Learn More About Legionnaires’ Disease

Legionnaire’s disease is a potentially life-threatening form of pneumonia resulting from contact with a bacteria most commonly found in commercial and domestic water-use systems. Prompt medical care is called for. If you think that you may be at risk for a serious respiratory disorder, contact a Baptist Health pulmonologist today.

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