How is Legionnaires disease transmitted?
The disease is spread through the air from a water source. Most people contract Legionnaires’ disease by inhaling mist that comes from a water source (e.g. showers, cooling towers, whirlpool baths) contaminated with Legionella bacteria. In some cases, the disease may be transmitted by aspirating contaminated water. The normal presence of Legionella in such environmental sites as water and soil is not automatically associated with an outbreak of the disease. It appears that the Legionella microbe, in order to produce the disease, must reach the lungs. Inhalation of small particles of contaminated water (aerosols) or soil seems to be the key. Drinking contaminated water, as opposed to breathing in contaminated aerosols, has not been associated with Legionnaires’ disease. However, this possibility should not be entirely excluded.
