● Legionnaires’ disease is a potentially fatal lung infection (pneumonia) that is caused by the legionella bacteria.
● The disease is caught by breathing in small droplets of contaminated water.
● It is not contagious and cannot be spread directly from person to person.
● Initial symptoms include a high fever and muscle pain. Once the bacteria begin to infect people’s lungs, they may also develop a persistent cough and health officials say prompt treatment using antibiotics is essential to reduce the risk of death.
● Legionella bacteria is commonly found in sources of water including rivers and lakes but it can sometimes find its way into water supply systems including air conditioning systems and cooling towers.
● Large buildings, such as hotels, hospitals, museums and office blocks, are more vulnerable to legionella contamination because they have larger, more complex water supply systems in which the disease can spread quickly.
● The disease is three times more common in men than women and it mostly affects people aged 50 plus.
from NHS Choices