On August 20, the Michigan Department of Community Health confirmed two human cases of Eastern Equine Encephalitis in Kalamazoo County. A 61-year-old man is recovering from the illness while a 41-year-old man is in intensive care in a Kalamazoo County hospital.Both human cases have a history of local exposure to mosquitoes. These are the first human cases reported in Michigan since 2002. No further details about the two cases are being released.
A virus of birds that is spread by mosquitoes, EEE is a rare illness in humans, according to an MDCH press release. Only a few human cases are reported each year in the United States. People who become ill with EEE experience fever, headache, chills and nausea. In some cases, symptoms may progress to inflammation of the brain, signaled by disorientation, seizures and coma.
EEE is spread by mosquitoes and causes inflammation of the horses’ brains and leads to death in up to 90 percent of the cases, according to MDCH. People cannot get the disease from horses, only from mosquitoes. There is a vaccination available to aid in prevention of the disease in horses.
Clinical signs in horses include: depression, fever, weakness, sweating, dehydration, seizures, abnormal facial expressions, not feeding, head down, stumbling, blindness and circling. Often, the horse is down and unable to get up.
“The majority of the 2010 affected Michigan horses were not currently vaccinated against EEE,” said Dr. Steven Halstead, Michigan state veterinarian. “It is not too late to vaccinate horses against this deadly virus.”
EEE is a reportable disease that also affects poultry such as chickens and emus. Veterinarians are required by law to report cases of EEE. Livestock owners are also encouraged to report cases.
“We encourage diagnostic testing because EEE can look like rabies and although rabies is not common in horses, it is fatal and is contagious from horses to people,” Dr. Halstead said.
The MDCH and the Michigan Department of Agriculture are continuing to receive reports of cases of EEE in horses in Southwest Michigan, including Barry, Calhoun, Cass, Kalamazoo and St. Joseph counties. EEE is one of the most dangerous mosquito-borne diseases in the U.S., killing one third of those hospitalized with the infection, and often leaving survivors with lasting brain damage.
In addition to the human cases, 18 horses have tested positive for the virus, and MDA has received more than 50 additional reports of horse deaths.
The southwestern region of the state has experienced outbreaks of this mosquito-borne disease in the past with the most recent outbreaks occurring in the early 1980’s and mid-1990’s. Mosquito-borne illness will continue to be a risk in Michigan until late fall when nighttime temperatures fall below freezing.
Communities and land owners in high-risk areas may consider the targeted application of insecticides to reduce the number of biting mosquitoes. The Michigan Mosquito Control Association maintains a list of licensed mosquito control applicators on its website at www.mimosq.org.
Steps you should take to protect yourself include:
- Use repellent: When outdoors, use insect repellent containing DEET, picaridin, IR3535 or oil of lemon eucalyptus on exposed skin and/or clothing. The repellent/insecticide permethrin can be used on clothing to protect through several washes. Always follow the directions on the product label.
- Stay indoors when mosquitoes are biting: Mosquitoes are most active at dusk and dawn.
- Wear protective clothing: Wear long sleeves and pants when weather permits.
- Install and repair screens: Have secure, intact screens on windows and doors to keep mosquitoes out.
- Keep mosquitoes from laying eggs near you: Mosquitoes can lay eggs even in small amounts of standing water. Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets, barrels and tires. Change the water in pet dishes and replace the water in bird baths weekly. Drill holes in tire swings so water drains out. Empty children’s wading pools and store on their side after use.
For more information on the human health impact of EEE, please visit the Centers for Disease Control and Prevention’s EEE website at http://www.cdc.gov/easternequineencephalitis/. For updates on equine and human cases of EEE and other mosquito-borne diseases in Michigan, visit the Emerging Diseases website at http://www.michigan.gov/emergingdiseases.
