MSU entomologist receives grant to study control of Eastern Equine Encephalitis

Ned Walker, a professor in the MSU Department of Entomology, has received a $100,000 grant from the Centers for Disease Control and Prevention to examine insecticide-treated resting stations that kill mosquitoes carrying Eastern Equine Encephalitis.

Ned Walker, a professor in the MSU Department of Entomology
Ned Walker, a professor in the MSU Department of Entomology.

EAST LANSING, Mich.Ned Walker, a professor in the Michigan State University Department of Entomology, has received a $100,000 grant from the Centers for Disease Control and Prevention (CDC) to examine insecticide-treated resting stations that kill mosquitoes carrying Eastern Equine Encephalitis (EEE).

A neurological disease, the EEE virus infects the brain and can cause fever, headache, seizures and coma. People 50 and older are at greatest risk of developing serious complications.

“EEE is a very serious problem for both human health and agriculture that was previously very rare in Michigan,” Walker said. “With changing climate patterns, however, including warmer and wetter weather, we’re seeing ideal conditions for mosquitoes to thrive in recent years.”

EEE is one of the most dangerous mosquito-borne diseases in the U.S. There is a 33% fatality rate in humans who become ill and a near total fatality rate for horses. Survivors of symptomatic EEE infections are often left with permanent neurological damage.

In the initial stage of the project, Walker will examine environmentally friendly insecticides by constructing resting stations and testing whether the chosen chemicals are suitably toxic. He will also determine how long the chemicals last after treated resting boxes are deployed.

The research team will also be collecting Culiseta melanura mosquitoes, the species responsible for spreading EEE, at identified sites and testing for population size, age and infection with the virus.

Historically EEE cases are rare in Michigan, however the state has been one of the prime locations of human infections across the country. In 2019, Michigan represented 25% of EEE cases in the U.S.

As of Oct. 1, there were 36 cases in 15 Michigan counties in 2020 — 34 horses and two deer, according to the Michigan Department of Health and Human Services. To curb further spread, the state of Michigan has conducted aerial sprays of more than 462,000 acres as of Sept. 24.

While serious cases are rare — only 38 were reported across the country in 2019 — there is no cure for EEE, so prevention is the best course of action.

But that’s no easy task. Walker said that high water tables and warmer-than-usual weather in Michigan have created an ideal environment for mosquito populations to increase and sustain.

“It’s important to get out in front of the problem,” Walker said. “Late-season sprays are often reactive and ineffective at controlling the mosquito population, so early-season interventions will be essential to develop moving forward.”

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