Legionnaires' disease is on the rise in Michigan and this expert explains why

The Michigan Department of Health and Human Services and local health departments are investigating a spike in Legionnaires Disease in dozens of counties. 

During the first two weeks of July, the number of cases are up 596 percent compared to this time last year.

The large amount of workers returning to the office as well as the amount of rain southeastern Michigan has received lately could be the reasons why.

"That's compared to 2020 and everything in 2020 is different - if you look at 2019 - it's up about 160 percent," said Dr. Matt Sims.

A total of 107 cases is still high but Sims, of Beaumont Royal Oak, says there is likely a reason. Legionnaires' Disease, spread by inhaling droplets of waterborne bacteria, is associated with air conditioning in large buildings.

Last year, many people worked from home. Now that employees are going back to work, they are being exposed.

"Buildings are being reactivated after being dormant for a while," he said. "You might have some standing water in systems you normally wouldn't. The other is, it's also the period of time when air conditioners turn on automatically, and that happens in the beginning of July, that's true."

The Legionella bacteria can also spread exposure from hot tubs, plumbing issues, and standing floodwaters, which we have experienced quite a bit lately in metro Detroit.

It's important to know it's not spread person to person or by home air conditioners, which don't use water to cool.

The state's chief medical director Joneigh Khaldun wants people over 50, especially those with weakened immune systems to be aware and doctors to remain vigilant, testing and treating when patients, who complain of these symptoms.

"Chest pain, problems breathing, fever, sometimes diarrhea is associated with this one, shortness breath - these are the typical things we see with pneumonia," he said.

The older you are, the more at risk you are, Sims said.