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Legionnaires’ disease is a kind of bacterial pneumonia
Although there have been documented cases of this form of pneumonia
that occurred as far back as 1947, the germ (bacterium) that causes it
was not identified until 1976, when a number of cases occurred in
Philadelphia among people attending an American Legion convention. The
disease was then named after this outbreak. The bacterium was later
named Legionella pneumophila.
The illness caused by the bacteria may vary in severity
Legionnaires’ disease causes pneumonia that can sometimes be severe
and lead to death. More serious illness tends to occur in men over 50,
smokers, people with diabetes mellitus, chronic lung disease, or kidney
disease. People with an underlying cancer or immune problem may also be
at increased risk of Legionnaires’ disease.
The Legionella bacterium is common in the environment
It can be easily found in aqueous (water) environments, such as air
conditioning cooling towers, hot and cold water taps, showers,
humidifiers, whirlpool spas, creeks, and ponds.
People get Legionnaires’ disease from inhaling contaminated water particles
The Legionella bacterium is spread by the release of small droplets
of contaminated water into the air from air conditioning cooling towers,
showers, misters, humidifiers, etc. To cause illness, infected water
droplets must be inhaled (breathed in) by a susceptible person. The
disease is not spread from person to person.
Symptoms usually occur 2 to 10 days after coming in contact with Legionella and may include:
Legionnaires’ disease is treated with antibiotics
The health department may investigate certain cases of Legionnaires’ disease
If more than one case of Legionnaires’ disease occurs from a common
exposure, the health department may look for a possible environmental
source of contaminated water.
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