Eighteen adults in Washtenaw County have been diagnosed with Legionnaires’ disease (Legionella pneumonia) in 2018. No deaths have been reported.
The Health Department continues to look for sources of common exposure, however, to date, none have been found.
Typically, 8 to 10 Washtenaw residents are diagnosed with Legionnaires’ each year, therefore 18 is more than usual. Although a few cases occurred early in the year, over 80 percent have been diagnosed since July 2018. All 18 people have been hospitalized.
Three individuals had travel exposure outside of Michigan.
Overall, this increase corresponds with national increases in Legionnaires’ disease.
Legionnaires’ disease is a very serious type of pneumonia (lung infection) caused by bacteria called Legionella. Legionnaires’ disease can cause pneumonia symptoms, including:
- Muscle aches
- Shortness of breath
Most healthy people do not get Legionnaires’ disease after being exposed to Legionella. Being 50 years or older or having certain risk factors, such as smoking, chronic lung disease, or a weakened immune system, can increase your chances of getting sick.
Legionnaires’ disease is treated with antibiotics. Most people who get sick need care in a hospital but make a full recovery. However, about 1 out of 10 people who get Legionnaires’ disease will die from the infection.
How Legionnaires’ Is Spread
In nature, Legionella bacteria live in fresh water and rarely cause illness. In man-made water systems, such as large plumbing systems, cooling towers, whirlpool spas and decorative fountains, Legionella can grow if water is not properly maintained. These manmade water sources become a health problem when small droplets of water that contain the bacteria get into the air and people breathe them in. In rare cases, someone breathes in Legionella while they are drinking water and it “goes down the wrong pipe” into the lungs. In general, people do not spread Legionnaires’ disease to other people.