A small portion of northern Washtenaw County may receive aerial treatment tonight to control for mosquitoes that carry deadly Eastern Equine Encephalitis, or EEE. The Washtenaw County zone will only be sprayed tonight if, due to weather, it is not possible to spray the areas in southwest Michigan prioritized for treatment tonight. All aerial treatment will begin at dusk and conclude by 4:30 am. Schedule updates are available at www.Michigan.gov/eee.
Washtenaw County has no human or animal cases of EEE at this time. The area targeted for spraying is a 2.5 mile radius around a confirmed animal case in neighboring Livingston County. This area includes parts of Livingston County, as well as northern Northfield and Webster Townships in Washtenaw County. This decision was made in collaboration with the Michigan Department of Health and Human Services (MDHHS).
An aerial spray will decrease the mosquito population and reduce the risk of humans or animals contracting EEE. Typically, 5-10 cases of EEE are reported in the United States each year. This year, Michigan has had 9 human cases resulting in 3 fatalities, as well as 33 animal cases.
About Merus 3.0
The product MDHHS is using for aerial treatment is called Merus 3.0. It will be sprayed by a low-flying aircraft at a very low volume of around one tablespoon per acre. Merus 3.0 is registered with the EPA. It is labeled for public health use over residential areas and is approved for use over organic crops.
No short-term or long-term risks to human health are expected during or after spraying. While it is not necessary to bring animals indoors during spraying, concerned pet owners can bring animals inside during spraying.
Application conducted at night will minimize risk to daytime foragers such as bees. The product will dry quickly and should not pose long term risk. Beekeepers wanting to further minimize the risk that the product would be drawn into a colony can reduce entrances to their colonies to minimize air movement into the colony, or cover colonies during an application using a damp cloth -- burlap is often recommended.
Similar products are used and have been proved effective in other states, including Massachusetts. In Massachusetts, officials have been monitoring approximately 600 honeybee colonies and have not observed problems.
Large water bodies will be avoided by MDHHS during spraying. The active ingredients in Merus 3.0 break down rapidly in surface water and are not expected to cause adverse effects.
EEE is one of the most dangerous mosquito-borne diseases in the United States, with a 33 percent fatality rate in people who become ill. People can be infected with EEE from the bite of a mosquito carrying the viruses. People younger than age 15 and over age 50 are at greatest risk of severe disease following infection.
Signs of EEE infection include the sudden onset of fever, chills, body and joint aches, which can progress to a severe encephalitis, resulting in headache, disorientation, tremors, seizures, and paralysis. Anyone who thinks they may be experiencing these symptoms should contact a medical provider. Permanent brain damage, coma and death may also occur in some cases.
More information, including a Frequently Asked Questions document in English, Spanish, and Arabic, are available at Michigan.gov/EEE.
Washtenaw County Health Department
The Washtenaw County Health Department promotes health and works to prevent disease and injury in our community. Our mission is to assure, in partnership with the community, the conditions necessary for people to live healthy lives through prevention and protection programs.
The Washtenaw County Health Department has achieved national accreditation through the Public Health Accreditation Board. Visit us at washtenaw.org/health or call 734-544-6700.