The bacteria that cause Legionnaires' Disease have been detected in water samples at the Minneapolis Veterans Medical Center, and officials said they are taking steps to eliminate the pathogen.

No illnesses have been discovered.

VA officials said routine testing on Nov. 19 found the type of Legionella bacteria that cause most human illness in 5 out of 40 samples from the hospital's water system. The hospital has since installed filters on taps and shower heads and is flushing the water system to eliminate the bacteria.

First identified in 1976 after an outbreak at an American Legion convention in Philadelphia, the Legionella bacterium causes 8,000 to 18,000 hospitalizations a year in the United States. Prompt treatment with antibiotics typically cures the infection.

The bacteria are found naturally in the environment, usually in warm water. The infection does not spread from person to person, but is transmitted when people inhale droplets or warm vapor that contain the bacteria.

The Minneapolis VA conducts quarterly testing for the bug, and officials said they aren't sure why it turned up now, though it may be because the hospital is using a new testing service, they said.

Legionella was found in 12 of 40 water samples. Five of those had Legionella pneumophila serotype 1, the strain that causes most human illness. Seven were other serotypes or other Legionella species that rarely cause human illness or are not known to do so.

No cases of Legionnaires' disease have ever been associated with the hospital, according to hospital records.

Josephine Marcotty • 612-673-7394