By Kevin Walker
LANSING, Mich. – The Michigan Dept. of Agriculture and Rural Development(MDARD) announced early this month that Eastern Equine Encephalitis (EEE), a deadly mosquito-borne disease, was found in Baraga County in Michigan’s Upper Peninsula.
According to the announcement on Oct. 2, not only was this was the first case of EEE in the U.P. this year, it was also the first time the disease has ever been found in Baraga County. The case indicates that the mosquitoes carrying EEE continue to be active. Generalized weather reports have more recently indicated that temperatures in the state last week were easily high enough that mosquitoes could still be active. Experts say mosquitoes will be active until there is a hard freeze, with temperatures going down to at least 28 degrees for several hours.
State veterinarian Nora Wineland explained that the pattern for EEE this year was a little bit different, with the disease occurring farther north than it did last year. EEE is a dangerous, zoonotic disease that is typically seen in the state from late summer to early fall. Temperatures in the state vary from locality to locality. Even in the more northern parts of the state, local temperatures around lakes can sometimes be higher than other places. In any event, she said, it is worth it to get a horse vaccinated, since a horse has a 90 percent chance of dying if it does contract a case of EEE.
“The vaccine isn’t that expensive,” Wineland said. “Horse owners should work with their veterinarians as to when they should vaccinate their horses.”
Last year, Michigan saw 50 cases of EEE in animals and a record 10 human cases. On average, one third of human cases ends in death. So far this year, there have been two human cases and 36 animal cases, in 13 counties. The human cases were confirmed in residents of Barry and Montcalm counties and the Montcalm County resident has died. Montcalm County had eight animal cases, Clare County four, Oakland County four and Kent County three. Cases have also been found this year in Allegan, Calhoun, Ionia, Jackson, Livington, Mecosta and Newaygo counties. Two of the animal cases were found in deer. The state completed an aerial spraying program late last month.
“There are still mosquitoes out in various parts of the state, but I couldn’t tell you exactly where due to local temperature variations,” Wineland explained. “We advise people to work with their veterinarian to work out their individual situation.”
Although EEE exists earlier in the warm season, cases in horses and people tend to show up later in the summer, Wineland stated. That’s because the kind of mosquitoes that bite horses and people circulate a little later in the summer.
Beside having a vaccination program for horses, Wineland advises that people take common sense steps to prevent the prevalence of mosquitoes on their property, including eliminating standing water sources and using mosquito repellent on themselves with an approved active ingredient such as DEET. She also advises the use of mosquito repellent approved for use on horses and using fans in barns overnight to deter mosquitoes.
More information about EEE can be found at www.michigan.gov/emergingdiseases.