What causes legionellosis/legionairre's disease?

Bacteria: Legionella is a bacteria that can be treated with a variety of antibiotics including doxycycline, levaquin, (levofloxacin) erythromycin, and others.

Legionella bacteria: Legionellosis or Legionnaire's disease is a type of pneumonia that is caused by legionella bacteria. It is spread through mist. Those who tend to be at risk may have poor immune systems, chronic lung conditions, heavy tobacco users or are over age 50. When present, sx's may include fever, chills, cough (may be productive of sputum or be bloody), difficulty breathing, confusion, muscle aches, chest