MDHHS alerts residents to be aware of legionellosis

The Michigan Department of Health and Human Services (MDHHS) is reminding residents to be aware of legionellosis, a respiratory infection caused by Legionella bacteria.

The symptoms of legionellosis may manifest as Legionnaires’ disease, which includes symptoms such as fever, cough, shortness of breath, and pneumonia, or as Pontiac fever, which has similar symptoms but no pneumonia.

Legionella bacteria can grow in water systems during the summer and early fall when the water is warm and stagnant, making legionellosis more prevalent during this time.

Legionella bacteria is primarily transmitted to humans when they inhale water mist or vapor containing the bacteria.

Most healthy individuals do not become infected or sick after being exposed to Legionella. However, individuals over the age of 50 with underlying conditions are at a higher risk of getting sick.

There have been 186 confirmed cases of legionellosis have been reported in Michigan this year, compared to 196 cases in 2022. 

This year’s cases are lower than the previous five-year (2018-2022) average of 234 confirmed legionellosis cases.

"If you are at risk and may have been exposed to Legionella, it is important to monitor your symptoms and contact your health care provider if you become ill," said Dr. Natasha Bagdasarian, MDHHS chief medical executive. "Legionnaires disease is treatable with antibiotics and health care providers are required to report cases to the health department."