Cases of legionellosis are up in Kent County, in Michigan, and across the country.

Last week, the Michigan Department of Health and Human Services announced that there have been 140 confirmed cases of legionellosis reported in Michigan so far this year.

Kent County has had 10 reported cases.

Others areas with a high number of confirmed cases include 19 in Oakland County, 16 in Wayne County, 13 in Macomb County, 11 in Genesee County and 10 cases in the City of Detroit.

Legionellosis is most common in the summer and early fall. Warming, stagnant water provides the best environment for the bacteria to grow in water systems.

The bacteria can lead to Legionnaires’ disease which is an infection with symptoms that include fever, cough and pneumonia. A milder form of legionellosis, Pontiac fever, is an influenza-like illness without pneumonia that resolves on its own.

Transmission to people occurs when mist or vapor containing the bacteria is inhaled. Legionellosis does not spread person to person.

The Michigan Department of Health and Human Services shares the risk factors:

  • Recent travel with an overnight stay.
  • Recent stay in a healthcare facility.
  • Exposure to hot tubs.
  • Exposure to settings where the plumbing has had recent repairs or maintenance work.

Most healthy people do not become infected after exposure. People at a higher risk include:

  • People over age 50.
  • Current or former smokers.
  • People with chronic lung disease.
  • People with weakened immune systems from diseases, such as cancer, diabetes or liver or kidney failure.
  • People who take immunosuppressant drugs.