Elkhart County to spray to combat spread of mosquito-borne virus

ELKHART COUNTY, Ind. (WNDU) – Following the confirmation of several cases of a deadly mosquito-borne virus, Elkhart County commissioners have decided on an aerial spray plan to limit the spread of the disease.

Eastern equine encephalitis, or EEE, has recently become a concern, particularly in southwestern Michigan, where several cases have been confirmed in humans.

Spraying to kill adult mosquitoes will begin Wednesday at dusk. If weather does not cooperate, Thursday is the backup application date.

Commissioners made the decision after consulting with the Centers for Disease Control and Prevention, Indiana State Department of Health, Elkhart County Health Department, Elkhart County Emergency Management and Purdue University Agriculture Extension office.

In Elkhart County, a total of eight horses have tested positive for the virus, as has one mosquito sample pool.

As a result, Elkhart County will join several counties in Michigan in spraying in an attempt to control the mosquitoes and protect residents.

Elkhart County's horse cases "are concentrated south of Bristol and west of Middlebury in an area often referred to as the 'fruit hills,'" according to a release issued by Elkhart County Emergency Management. The mosquito pool that tested positive was in the northwest portion of the county, near Boot Lake.

Elkhart County announced last week that it was looking into possible cases.

The chemical approved by commissioners is a pesticide called Dibrom, which will be applied in an ultra-low volume, or ULV, spray.

"ULV sprayers dispense very fine aerosol droplets that stay suspended in the air and kill adult mosquitoes on contact," the release says. "This is a tactic other states, including Michigan, Massachusetts and Rhode Island, have recently employed to combat EEE."

Dibrom has been Environmental Protection Agency-registered for use in the U.S. since 1959 and immediately begins to break down after being released into the open air. It also breaks down quickly in water and sunlight, according to the release.

Organic farms registered on Field Watch will not be sprayed. Organic farms not so registered must call Jeff Burbrink at the Purdue University Extension in Goshen by Tuesday at 574-533-0554.

The release says residents should take actions to protect ornamental fish ponds and beehives.

Spraying is expected to kill 90% of mosquitoes, but Elkhart County residents are still encouraged to take precautions, including using EPA-approved insect repellent and wearing long sleeves and pants.

The full release from Elkhart County Emergency Management is reproduced below:

The Elkhart County Health Department and the Indiana State Department of Health (ISDH) have been working together to monitor eastern equine encephalitis (EEE) activity in Elkhart County. So far in 2019, a total of eight horses have tested positive for EEE, along with one mosquito sample pool in Elkhart County.
Due to the detection of EEE activity in Elkhart County and the occurrence of human EEE cases in nearby Michigan counties, the Elkhart County Commissioners have decided to perform targeted mosquito control utilizing aerial spraying to help protect residents from EEE. While rare, EEE virus can cause serious illness and has a fatality rate of about 33 percent in people.
The horse cases are concentrated south of Bristol and west of Middlebury in an area often referred to as the “fruit hills.” The positive mosquito pool was located in the northwest quadrant of the county near Boot Lake. These areas include numerous freshwater, hardwood swamp and bog areas and will be targeted with aerial spraying.

Mosquito control professionals will apply an approved pesticide, Dibrom, as an ultra-low volume (ULV) spray. ULV sprayers dispense very fine aerosol droplets that stay suspended in the air and kill adult mosquitoes on contact. This is a tactic other states, including Michigan, Massachusetts and Rhode Island, have recently employed to combat EEE. Dibrom has been registered by the U.S. Environmental Protection Agency (EPA) since 1959 for use in the United States. Dibrom immediately begins to break down upon release of the spray droplets in the open air and breaks down rapidly in water and in sunlight.

The decision to implement the additional control measure was made by the County Commissioners in consultation with the Centers for Disease Control and Prevention (CDC), ISDH, Elkhart County Health Department, Purdue University Ag Extension office, and Emergency Management. Protecting the public health is the primary goal of the decision.

County officials are targeting Wednesday October 2, at dusk, for the application. Thursday October 3 is the backup application date if weather prevents the Wednesday application. Residents should take actions to protect ornamental fish ponds and bee hives. Organic farms registered on Field Watch will not be sprayed. If an organic farm operation is not registered with Field Watch, contact Jeff Burbrink at Purdue University Extension, Goshen, 574-533-0554, by Tuesday afternoon.

While the spraying is expected to kill 90 percent of mosquitoes, Elkhart County residents are urged to continue to take precautions until the first hard freeze, including:

- Avoiding areas where mosquitoes breed,
- Staying indoors when mosquitoes are active,
- Utilizing an EPA-registered insect repellent; and
- Wearing long-sleeved shirts and pants in areas of high mosquito activity.

In addition, residents are urged to check their property for mosquito breeding sites and take the following actions:
- Empty containers that are holding water,
- Unclog gutters,
- Keep overgrown vegetation mowed,
- Dispose of old tires and
- Maintain screens in doorways and windows.
- Swimming pools should be maintained clean and operational;
- Ornamental ponds should be aerated to prevent the collection of mosquito larvae.

For more information about EEE, visit the CDC’s website at https://www.cdc.gov/easternequineencephalitis/index.html.