Michiganders urged to stay indoors as officials race to stop the spread of a dangerous mosquito-borne disease - CNN

"MDHHS continues to encourage local officials in the affected counties to consider postponing, rescheduling or cancelling outdoor activities occurring at or after dusk, particularly those involving children to reduce the potential for people to be bitten by mosquitoes."

Twenty-two horses across 10 counties have also been confirmed to have EEE -- twice the number of animal cases seen in Michigan this time last year.

The state is conducting aerial treatment across several "high-risk areas" in an effort to reduce the number of mosquitoes spreading the virus.

Five confirmed human cases of EEE have been reported to the US Centers for Disease Control and Prevention this year, as of September 9.

Three cases were reported in Massachusetts and two in Wisconsin.

There are typically only 5 to 10 human cases reported in the United States each year, according to the CDC.

About 30% of all cases result in death.