Esmeralda Avila 4/4/16

Causes and Pathophysiology

Legionnaire's is a type of pneumonia caused by the bacteria legionella. Legionella can grow in warm water, such as hot tubs, cooling towers, hot water tanks, and large plumbing systems. People can be exposed to this bacteria by breathing in the mist or vapor of contaminated water. Legionella does not spread from one person to another. Once the bacteria reaches the lungs, the organisms are phagocytosed by alveolar macrophages, where they release pernicious factors that allow this bacteria to survive and replicate.
It's hard to diagnose this type of pneumonia, because it has many of the same signs and symptoms of other pneumoniae. Some signs and symptoms include:

  • High fever
  • Chills
  • Coughing
  • Muscle aches and headaches
  • Shortness of breath
Most people exposed to this bacteria do not get sick from it. You have a higher risk of getting sick if you:

  • Are older than 50
  • Are a current or former smoker
  • Have a chronic lung disease
  • Have a weak immune system

The best way to treat Legionnaire's is by taking antibiotics. Most people will be cured after a few weeks, but some will have complications, including lung failure or even death. 1 out of 10 people who get this disease will die due to complications from their illness.