Legionnaires' Disease

What is Legionnaires' disease?

Legionnaires' disease is inflammation and infection of the lungs caused by bacteria called legionella. It causes a type of pneumonia.

How does it occur?

Legionella bacteria live in soil and water. The bacteria grow easily in warm, stagnant water, such as the water in some plumbing systems, hot water tanks, whirlpool baths or spas, and cooling towers of large air-conditioning systems. There is no evidence that bacteria are spread from air conditioners in cars or from household window air-conditioning units.

Legionnaires' disease occurs most often in summer and fall. During these seasons, people are more exposed to air conditioners and hot tubs, which may be contaminated with the bacteria.

The disease does not appear to spread from person to person.

You have a higher risk of having Legionnaire's disease if:

You are over 65 years old.
You smoke.
You have a chronic lung disease.
Your immune system doesn't work normally, for example, because of cancer or cancer therapy, diabetes, kidney failure, AIDS, or use of steroid drugs in high doses.

What are the symptoms?

The first symptoms of this disease are:

fever and chills
dry cough (a cough that doesn't produce sputum)
headache
general ill feeling
muscle aches.

Symptoms that occur 1 to 2 days later may include:

spiking fever (fever that is high at times and then comes down)
repeated chills
chest pain
confusion
diarrhea
abdominal pain
blood in the urine.

How is it diagnosed?

Your health care provider will ask about your symptoms and examine you. Tests you may have are:

blood tests
urine test
tests of a sputum sample (a sample of mucus coughed up from deep in your lungs)
chest x-ray.

How is it treated?

If your health care provider thinks you may have Legionnaires' disease, your treatment will begin right away, before all test results are back. If you are very sick, you will stay in the hospital, where you will be given intravenous (IV) antibiotics. If you are less severely ill, you may be able to take oral antibiotics and not have to stay in the hospital.

Treatment may also include replacing body fluids lost because of high fever, rapid breathing, and sweating. You may need oxygen to help your breathing during the first few days.

How long will the effects last?

Recovery takes 1 to 2 weeks with treatment. If you are over 60 years old or have other medical problems, it may take longer to recover.

How can I take care of myself?

Follow the treatment your health care provider prescribes.
If you have a fever above 100°F (37.8°C), stay in bed. When your temperature falls below 100°F (37.8°C), you may become as active as you comfortably can.
Drink more liquids (water, tea, or fruit juice) every day to help you cough up mucus more easily.
Cough up lung secretions as much as possible. Use cough medicine only if your provider recommends it.
Use a humidifier to increase air moisture. Avoid steam vaporizers because they can cause burns.
Ask your provider about taking aspirin, ibuprofen, or acetaminophen for fever or chest pain.
Use a heating pad on a low setting to reduce chest pain. Be careful not to fall asleep while you are using the heating pad.
Call your health care provider if you feel you are getting worse or if you are not getting better in 2 to 3 days.

What can be done to help prevent Legionnaires' disease?

There is no known way to prevent Legionnaires' disease.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File INF4523F.HTM Release 9.0/2006