State to spray for mosquitoes to prevent EEE

GRAND RAPIDS, Mich. (WOOD) — State health officials plan to start aerial sprays this week to kill mosquitoes and prevent them from infecting people with Eastern Equine Encephalitis.

The spray will start Wednesday evening, weather permitting, the Michigan Department of Health and Human Services announced Monday. It will cover 10 counties where EEE has already been found in horses this year:

The state conducted aerial mosquito treatments last year and is using the same product this time around — Merus 3.0. State health officials say it is a chemical that naturally occurs in chrysanthemum flowers and will not impact drinking water. A specialized aircraft will spray the ultra-low volume aerosol to kill mosquitoes on contact.

The sprays happen overnight, when mosquitoes are more active and honeybees, which can be harmed by the spray, are safely in their hives.

The state says there weren’t any adverse health effects to people caused by last year’s sprays. Those who are sensitive to the insecticide pyrethrins should stay inside so they aren’t exposed.

Last year, communities had the opportunity to opt out of the aerial spray. This year, the state issued an emergency order eliminating that option. That means the spray is mandatory everywhere the state has planned it.

“…In a normal situation, there are provisions in our pesticide rules for notification and exclusion options. Those rules have also always had a provision to that recognizes the importance of acting quickly in a public health emergency,” Brad Deacon, the director of legal affairs and emergency emergency Management for the Michigan Department of Agriculture and Rural Development, explained the move during a conference call with reporters Monday. “We have taken the step today to temporarily amend our rules so that we don’t have a barrier to prompt action by the state.”

If weather prevents the work Wednesday, MDHHS will provide updates on its website.

“We are taking this step in an effort to protect the health and safety of Michiganders in areas of the state where we know mosquitoes are carrying this potentially deadly disease,” Michigan’s chief medical executive Dr. Joneigh Khaldun said of the aerial treatment. “As people are spending more time outdoors because of COVID-19, they also need to be protecting themselves from mosquito bites.”


EEE is rare. Brendan Earl, supervising sanitarian with the Kent County Health Department, said only 4% to 5% of people infected will show symptoms. About 1% will develop serious symptoms, which can result in lasting physical ailments, neurological impacts or death.

Last year, 10 people in Michigan contracted it and six of them, all in southwest Michigan, died.

So far this year, no people have been infected with EEE, but it has infected and killed 22 horses. MDHHS says that’s about twice as many animal cases as the same time last year.

EEE is more deadly for horses than humans — about 90% of horses that develop symptom die — but horses can also get immunized, while there is no such vaccine for humans.

On Friday, MDHHS advised that outdoor activities happening around dusk be rescheduled, postponed or canceled to help prevent people contracting the disease, specifically noting sports involving children. In 2019, several West Michigan school districts scheduled football games to start earlier in the day so they would wrap up before peak mosquito hours.

Some school districts are doing the same thing this year. Administrators at Godfrey-Lee Public Schools in Wyoming say they plan to move up sport event times.

Horse owners are reminded to vaccinate the animals and keep them in the barn during peak mosquito hours. People should use mosquito repellent with DEET and wear long pants and shirts while outdoors to prevent bites. The Kent County Health Department says people should also avoid being outdoors after dusk.

“Make sure you have screens on your windows, they don’t have any holes in them. Make sure any kind of stagnant water around your house is dumped out. Dump out those bird baths, those old kiddie swimming pools; making sure your gutters aren’t holding standing water,” Earl, the health department sanitarian, listed.

He said the number of EEE cases this fall is especially alarming.

“Last year, we maybe thought was just the circumstances with the rainfall and habitat and temperatures. It was very out of the ordinary. Now that we’ve seen it two years in a row, we are quite concerned,” Earl, the health department sanitarian, said.

But he also said the disease is fairly avoidable if Michiganders are aware and vigilant. Earl said officials don’t want to scare people but do want EEE to be taken seriously.

“As long as you’re aware of it and take appropriate precautions, a lot of people don’t show symptoms. Only a few of those people have serious symptoms. The point is whether it’s one two, three, every life is precious. So if you can take these easy steps to protect your family, that is the best way to go,” Earl said.

If you have questions about EEE, you can call the MDHHS hotline during regular business hours at 888.535.6136 — that’s the same number that takes questions about COVID-19.