The disease is highly contagious. The bacteria which causes this disease is only harmful when tiny droplets of water floating in the air containing the bacteria are inhaled, and does not cause harm when it is present in drinking water.
The bacteria has been found in water systems and can survive in the air conditioning systems of large buildings. Risk factors for infection include smoking, copd, renal failure, cancer, diabetes and alcoholism. Legionnaires disease
An acute, sometimes fatal, pneumonia-like bacterial infection characterised by high fever, malaise, muscle aches, respiratory disorders and headache. It is named for an outbreak at the 1976 philadelphia convention of the american legion.