Legionnaires' Disease
Legionnaires’ disease is a serious type of pneumonia caused by Legionella bacteria. It develops when a person inhales contaminated water droplets, often from sources like cooling systems, showers, or hot tubs. While not spread person-to-person, it can cause severe lung infection, especially in older adults or those with underlying health conditions.
Quick Facts
- A severe form of bacterial pneumonia
- Caused by Legionella bacteria found in water systems
- Spread through inhaled water droplets, not person-to-person
- More common in older adults and those with weakened immune systems
- Early treatment with antibiotics is important
Symptoms
Symptoms usually begin 2 to 10 days after exposure and may include:
- Cough (sometimes with mucus)
- Fever and chills
- Shortness of breath
Other symptoms may include muscle aches, headache, fatigue, confusion, or diarrhea. Legionnaires’ disease can sometimes be mistaken for flu, COVID-19, or other types of pneumonia.
Causes
Legionnaires’ disease is caused by inhaling small droplets of water contaminated with Legionella bacteria.
Common sources include:
- Cooling towers and air conditioning systems
- Showers and faucets
- Hot tubs or spas
- Large plumbing systems in buildings
The bacteria grow best in warm water environments that are not properly maintained.
Legionnaires’ disease has been identified in outbreaks across the United States, including in California. Cases have been reported in a variety of settings such as hotels, public buildings, and healthcare facilities, highlighting the importance of proper water system maintenance.
Risk Factors
You may be at higher risk if you:
- Are over age 50
- Smoke or have a history of smoking
- Have chronic lung disease
- Have a weakened immune system
- Have underlying conditions such as diabetes or kidney disease
Treatments
Legionnaires’ disease is treated with antibiotics and often requires prompt medical care.
Most patients need prescription antibiotics, and some cases may require hospitalization, especially if symptoms are severe. Supportive care, including oxygen therapy and fluids, may also be needed.
Early diagnosis and treatment significantly improve outcomes.
When to Seek Care
Seek medical care right away if you have symptoms of pneumonia, such as fever, cough, and shortness of breath, especially if symptoms are worsening or you are at higher risk.
