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February 9, 2012

Legionellosis
(Legionnaires' Disease and Pontiac Fever)

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Prognosis of Legionnaires' Disease

How serious is it? What is the treatment?

Legionnaires' disease can be very serious and can cause death in up to 5% to 30% of cases. Most cases can be treated successfully with antibiotics (drugs that kill bacteria in the body), and healthy people usually recover from infection.

Where do Legionella bacteria come from?

The Legionella bacteria are found naturally in the environment, usually in water. The bacteria grow best in warm water, like the kind found in hot tubs, cooling towers, hot water tanks, large plumbing systems, or parts of the air-conditioning systems of large buildings. They do not seem to grow in car or window air-conditioners.

SOURCE: CDC

Legionellosis (Legionnaires' disease and Pontiac fever) facts

  • Legionellosis is an infection that is caused by a bacterium.
  • The bacterium thrives in the mist that is sprayed from air-conditioning ducts.
  • The bacterium can infest an entire building.
  • The illness takes two distinct forms: Legionnaires' disease and Pontiac fever.
  • Legionnaires' disease is the more severe form and can be fatal.
  • Pontiac fever is the far milder form of the illness.
  • Symptoms of Legionnaires' disease include fever, chills, and a cough.
  • At its worst, Legionnaires' disease can cause severe pneumonia and respiratory failure.
  • Although antibiotics are effective for treatment, the most useful approach is prevention.

What is legionellosis? What is the history of Legionnaires' disease?

Legionellosis is an infection that is caused by the bacterium Legionella pneumophila. The disease has two distinct forms:

  • Legionnaires' disease is the more severe form of the infection, which may involve pneumonia. The onset of this form of the disease is usually two to 10 days after infection but can occur up to 16 days later. Legionnaires' disease acquired its name in 1976 after an outbreak of pneumonia occurred among people attending a convention of the American Legion in Philadelphia. Later, the bacterium causing the illness was named Legionella pneumophila.
  • Pontiac fever is a milder illness that develops from hours to two days after initial infection and resolves spontaneously.
X-ray image of lungs of patient with Legionnaires' disease
X-ray image of lungs of patient with Legionnaires' disease; SOURCE: CDC



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Legionnaires' Disease

What is chronic cough?

Chronic cough is a cough that persists. Chronic cough is not a disease in itself; rather it is a symptom of an underlying condition. Chronic cough is a common problem and the reason for many doctor visits.

What are causes of chronic cough?

Some common causes of chronic cough include asthma, allergic rhinitis, sinus problems (for example sinus infection), and esophageal reflux of stomach contents. In rare occasions, chronic cough may be the result of aspiration of foreign objects into the lungs (usually in children). It is very important to see a doctor who may order a chest X-ray if a chronic cough is present. The following are common causes of chronic coughing.

  • Cigarette smoking actually is the most common cause of chronic cough.
  • Asthma is a disease of airways, resulting in difficulty breathing or wheezing often characterized by abnormal breathing...

Read the Chronic Cough article »







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