The Michigan Department of Health and Human Services confirmed on October 2 a person in Battle Creek who contracted Eastern Equine Encephalitis (EEE) has died, bringing the total number of human fatalities to four.
On October 8, MDHHS announced that it has completed all aerial pesticide spraying, which covered more than 557,000 acres across 14 counties.
The spraying is the state's attempt to curb the spread of Eastern Equine Encephalitis (EEE), a mosquito-borne illness that can be fatal in both humans and animals.
Here's what you need to know about EEE and the spraying.
This is a developing story. Check back here for more information throughout the week. Last update: Tuesday, October 8 at 3:00 p.m.
EEE is spreading
This is the first time in decades the state has used aerial pesticides to protect against mosquito-borne illnesses. The last time was in 1980.
Stopping EEE has become urgent. As of October 8, four people have died, and ten total illnesses have been reported. The deaths were in Calhoun, Kalamazoo, Van Buren, and Cass counties. 33 animals have also contracted the disease, and all those cases were fatal.
Symptoms of EEE include a sudden headache, high fever, chills, and vomiting. It may quickly progress into disorientation, seizures, and coma. It has a high fatality rate — approximately one third of patients with EEE die, and survivors may suffer permanent brain damage.
With potentially weeks to go before the first hard freeze kills off the mosquitoes, officials say they want to move now before the disease can spread further.
Parts of West Michigan are affected
So far, most of the human cases have been reported in West Michigan: three in Kalamazoo County, two in Cass County, and one each in Berrien, Barry, Calhoun, and Van Buren counties. Another 39 cases have been found in animals across 16 counties. 29 locations have been identified for the spray treatment.
Lynn Sutfin is a spokesperson for MDHHS.
"We have 15 different counties that could potentially have this aerial treatment in them," she says.
It was announced Monday evening that portions of Livingston and Washtenaw counties will be sprayed after an animal case was confirmed in Livingston.
But despite having the highest amount of cases, Kalamazoo County will not be sprayed. That's because too many residents chose to opt-out of the aerial spray, making it no longer effective to spray the small areas that didn't opt-out.
Spraying in the remaining areas was expected to begin Sunday night, but had to be delayed because of rain. Sutfin says weather is going to continue to be a factor in the timeline of the process.
"Ideally, we would be completed by the end of this week," says Sutfin.
The chemical is organic and EPA-approved
The pesticide being used is called Merus 3.0, "an EPA-registered, organic botanical adult mosquito insecticide containing five percent pyrethrins which are naturally found in chrysanthemum flowers," according to the MDHHS.
Spraying will occur from dusk to dawn, or approximately 8 p.m. to 4:30 a.m. This way, it will occur when mosquitoes are most active, but bees and other insects that could be harmed are least active.
Some people are concerned about the unintended impact on other insects and wildlife. The nonprofit Kalamazoo Nature Center requested an opt-out, saying it wants to know more about the potential effects on wildlife already facing habitat loss.
Stewardship Field Director Ryan Koziatek says he's concerned about potential stress on other insects and aquatic animals. He adds killing off mosquitoes could also affect some birds, which are feeding on insects as they prepare to migrate.
Merus 3.0 is safe for humans and pets, and MDHHS says no specific cautions need to be taken during the spraying. If you are concerned, however, they suggest staying inside, closing windows and doors, and covering pools and fish ponds.
Spraying will not completely eliminate EEE
The aerial spraying will not kill every mosquito in the area, and officials are urging people to continue to take precautions.
That includes using insect repellants with the active ingredient DEET, limiting time outdoors between dusk and dawn when mosquitoes are most active, and maintaining window and door screens to keep mosquitoes out of the home.
If you or anyone you know begins to experience symptoms (headache, high fever, chills, and vomiting possibly followed by disorientation or seizures), contact a doctor immediately.
This post was updated Tuesday Oct. 8 at 3:00 p.m.