Mosquito Mayhem

Michigan resident infected with Eastern equine encephalitis


LANSING– Health officials from the Michigan Department of Health and Human Services (MDHHS) and Allegan County Health Department have confirmed an infection of Eastern equine encephalitis (EEE) in an Allegan County resident. The individual was hospitalized in late August with a neurologic illness.
EEE is one of the most dangerous mosquito-borne diseases in the U.S., with a 33 percent fatality rate. The disease can often leave survivors with lasting brain damage.
The southwestern region of the state has experienced outbreaks of this mosquito-borne disease in people and horses in the past, with the most recent outbreaks occurring in the early 1980s, mid-1990s and 2010. This is the first human case reported in Michigan since 2016, when three people were infected. Mosquito-borne illness will continue to be a risk in Michigan until late fall when nighttime temperatures consistently fall below freezing. Michigan residents are reminded to protect themselves against mosquito bites.
“There is still plenty of mosquito season left in Michigan,” said Dr. Eden Wells, MDHHS chief medical executive. “When outdoors, Michigan residents are urged to take precautions to protect themselves and their families from mosquito bites including using mosquito repellent and wearing long pants and long sleeves.”
Horse owners should note that EEE can also cause neurologic illness in horses. However, vaccination can protect horses from infection with EEE.
EEE is a virus of birds that is spread by mosquitoes near swamps and bogs. Human cases are rare, with only a few cases reported each year in the U.S. People who become ill with EEE may experience fever, headache, chills and nausea. In some cases, symptoms may progress to inflammation of the brain, signaled by disorientation, seizures and coma. Physicians treating patients with these symptoms should consider testing for EEE and other mosquito-borne viruses and should report suspected cases to their local health department.
As a reminder, West Nile virus is continuing to cause illness in people across the state, with a total of 44 cases and two fatalities reported to date. WNV has also been identified in 149 mosquito pools, 115 birds and one horse throughout the state.  
Steps people should take to protect themselves include:

• Avoid being outdoors at dusk and dawn when mosquitoes are most active. 
• Wear light-colored, long-sleeved shirts and long pants when outdoors.
• Apply insect repellents that contain the active ingredient DEET or other EPA- approved product to exposed skin or clothing, always following the manufacturer’s directions for use.
• Use nets and/or fans over outdoor eating areas.
• Maintain window and door screening to help keep mosquitoes out of buildings.
• Empty water from mosquito breeding sites such as buckets, unused kiddie pools, old tires or similar sites where mosquitoes lay eggs.

For more information on EEE, visit the Centers for Disease Control and Prevention’s EEE website at Cdc.gov/easternequineencephalitis.
For updates on equine and human cases of EEE, WNV and other mosquito-borne diseases in Michigan, visit the Emerging Diseases website at Michigan.gov/emergingdiseases.