Parts of Livingston County will be treated via aerial spraying for a mosquito-borne virus; however, local health officials say exactly when that will occur is still “up in the air”.

It was confirmed late last week that a horse in Hamburg Township had contracted Eastern Equine Encephalitis or EEE, which is the most dangerous mosquito-borne disease in the United States. The horse was euthanized and communities within Livingston County were identified as regions that will be sprayed with Merus 3.0. Merus 3.0 is an EPA-registered, organic botanical adult mosquito insecticide containing 5% pyrethrins which are naturally found in chrysanthemum flowers. Still, numerous residents have expressed concerns to their local officials and over social media about the pesticide and its effects.

But Livingston County Director of Environmental Health Matt Bolang tells WHMI the dosage being used is very small, about one tablespoon per acre, and will occur at night, adding that if any residents were outside when the spraying occurred they “wouldn’t even feel it hit the ground”. Bolang says other states have used a similar product with a similar application method and conducted surveillance afterward, finding that it was very effective in killing mosquitos and did not have an adverse environmental impact. He notes that the environmental state of the pesticide degrades pretty quickly, adding that when it is airborne it will degrade within hours and, in the soil, it can last about a day or two but will break down shortly after that.

When Livingston County will be treated, however, is still unknown. Bolang says the treatment period is weather-dependent, noting that spraying cannot occur if it’s raining, windy or clouds are too close to the ground. He says Livingston County’s schedule will be reanalyzed day-to-day by the Michigan Department of Health and Human Services.

EEE has been confirmed in nine people across the state, which Bolang says is “unprecedented” at this time of the year. He says aerial spraying is a proactive measure that will limit the risk of contracting the disease. Bolang encourages community members to visit michigan.gov/eee for staying up to date on the state’s response to the outbreak and the schedule for aerial spraying. A link is posted below. (DK)