What is Legionnaires disease?
A. Legionnaires’ disease is a type of pneumonia that is caused by Legionella, a bacterium found primarily in warm water environments. Both the disease and the bacterium were discovered following an outbreak traced to a 1976 American Legion convention in Philadelphia. Pontiac fever, a flu-like illness, is also caused by Legionella organisms (legionellae), but is not as serious as Legionnaires’ disease. Most people who get Pontiac fever recover within five days, without having to be hospitalized.
The name “Legionnaires’ disease” was coined in 1976 after a respiratory disease affected many delegates attending a convention in Philadelphia held by the American Legion of Pennsylvania. Eventually, the bacteria that was responsible for the disease was isolated and named as Legionella pneumophila. Two distinct illnesses, Legionnaires’ disease and Pontiac fever, have been associated with the Legionella species. Legionnaires’ disease is a severe pneumonia. Pontiac fever is a mild, non-pneumonia influenza-like illness. It is not clear why the same causal agent can produce two distinct illnesses. In this document, we refer only to Legionnaires’ disease. Pontiac fever is apparently uncommon; only a few outbreaks have been reported in the world. One of them, a large one, was in Canada. What is the cause of Legionnaires’ disease? The bacterium responsible for Legionnaires’ disease belongs to the genus Legionella. There are approximately 35 Legionella species known to produce the disease. Leg
Legionnaires’ disease (LEE-juh-nares) is caused by a type of bacteria called Legionella. The bacteria got its name in 1976, when many people who went to a Philadelphia convention of the American Legion suffered from an outbreak of this disease, a type of pneumonia (lung infection). Although this type of bacteria was around before1976, more illness from Legionnaires’ disease is being detected now. This is because we are now looking for this disease whenever a patient has pneumonia. Each year, between 8,000 and 18,000 people are hospitalized with Legionnaires’ disease in the U.S. However, many infections are not diagnosed or reported, so this number may be higher. More illness is usually found in the summer and early fall, but it can happen any time of year.
Legionnaires Disease (LD) or Legionellosis is a life-threatening for of pneumonia that can affect anyone by attacking the lungs, but which principally targets those most susceptible (see later). The species responsible for LD is Legionella Pneumophila (lung-loving) and is one of a number of different legionella bacteria there are 57 in total! It is cigar-shaped and approximately 200th of one millimeter in size Note – Though caused by the same bacteria, the symptoms of Pontiac Fever are much milder and are not life-threatening. Lochgoilhead fever is another associated illness with similar mild symptoms but caused by a different legionella species, L. micdadei.
