A deadly mosquito-borne virus has not threatened Hillsdale County as of yet, but neighboring counties have been declared high-risk areas for the virus.
Jackson, Kalamazoo, and Calhoun counties are all considered high-risk areas for EEE, a mosquito-borne virus found mostly in the eastern regions of the United States.
Sixteen Michigan counties have been declared high-risk areas for the virus. The danger is ongoing, as nine human cases have been confirmed and three people have died to date. As of Oct. 2, 33 animal cases have been confirmed in 16 counties.
Hillsdale College Professor of Biology and resident virologist Silas Johnson said EEE is part of a group of viruses known as “alpha viruses.”
“They’re all very similar in terms of their structure and function,” Johnson said. “They share a common transmission mechanism via an insect vector.”
Johnson said EEE infects humans when a mosquito bites an animal, most commonly birds, that hosts the virus. The mosquito then delivers the virus to humans where it goes straight to the bloodstream.
A human is “a dead-end host,” according to Johnson. The virus will not spread further than its human host, so the disease is not contagious.
“Most people infected with EEE will be completely asymptomatic,” Johnson said. “A super tiny fraction — 3-5% of people — will actually show signs of any virus. And it’s usually not that severe: fever, chills, malaise, kind of like the flu. And then a very small fraction of those people actually come down with a really severe form.”
Johnson said the severe form of EEE mimics meningitis and encephalitis, which are both forms of inflammation of the brain and surrounding tissues. About 30% of people who contract the neurologic infection will die.
There is no cure for EEE. People under the ages 15 and above 50 are the most susceptible.
EEE also threatens animals, especially horses.
Public Information Officer for the Michigan Department of Health and Human Services Lynn Sutfin explained that this disease pops up in this region about once a decade. The weather and rainfall this year have both been factors, she said, but there is no specific reason it has occurred this year.
It is difficult to predict where it will appear next and in what volume. While the state has confirmed nine human cases, there are a total of 42 combined people and animal cases throughout 15 Michigan counties.
Due to the unpredictability and severity of the EEE virus, local Michigan high school athletic departments have had to postpone and reschedule athletic events.
Athletes who are likely to sweat with skin exposed are easy targets for the EEE-carrying mosquitoes, so the virus may infect a cross country or football athlete.
Fans attending athletic events are also susceptible. Schools have taken measures such as moving games scheduled for night hours to earlier afternoon times.
John Johnson, the director of broadcast properties for the Michigan High School Athletic Association, said the association has been busy “determining if there’s anything that needs to be done in terms of rearranging schedules and educating constituents.”
The department has kept in contact with and is receiving information from local athletic departments. Johnson praised the local communities for how they have dealt with the situation.
“Schools have really stepped it up in identifying risk and taking the necessary steps to keep everyone safe,” Johnson said.
Johnson added that he has never dealt with this virus on this level in his 32 years at his position.
According to a recent press release issued Sept. 27, aerial-spray treatment was conducted in 15 counties to combat the EEE virus. The treatment concentrated on lowering the mosquito population.
Because of the number of cases and the continuation of warm weather, the state has decided this is the best measure to take.
The spraying will take place at night, when mosquitoes are most active.
According to Sutfin, the state treated 128,000 acres in several counties during the night of Sept. 30. The state treated more high-risk counties on Oct. 1, but the process was cut short because of weather conditions.
Sutfin added that the spraying should be completed in all 15 counties by Oct. 2, weather permitting. After all of the counties have been treated, Sutfin said state officers will have treated 186,000 acres of land.
The spraying process uses Merus 3.0, an organic pesticide. There are no health risks expected from the use of this chemical. It is not expected to impact drinking or surface water, according to the press release.
The counties being sprayed are: Allegan, Barry, Berrien, Calhoun, Cass, Jackson, Kalamazoo, Kent, Lapeer, Livingston, Montcalm, Newaygo, St. Joseph, Van Buren, and Washtenaw.
Although there is no cure for EEE, there are several tangible ways to prevent contracting it. “Wear long sleeves and long pants when you’re outdoors, particularly at dusk and dawn,” Sutfin said. “Avoid being outside at dusk and dawn when mosquitoes are most active. You should also be looking at your house to make sure your window screens and your door screens are shut and in good repair so you aren’t getting mosquitoes inside. Every couple days, dump out any standing water, a mosquito’s breeding ground.”
For those interested in learning more information, Sutfin said they can go to Michigan.gov/EEE to view a map of affected counties.
