Eastern Equine Encephalitis

  • EEE Outbreak Information

    With the onset of colder weather throughout the state, the season of risk for arboviral illness has ended in Michigan.  However, cases from earlier in the year may continue to be investigated and reported.  The Arbovirus Update report below will be updated as needed rather than every week.

    So far in 2021, one person, nine horses, one deer, and five birds have tested positive for Eastern Equine Encephalitis (EEE).  If EEE is suspected in a horse, it should be reported to the Michigan Department of Agriculture and Rural Development at 800-292-3939 (support may be available to pay for testing).  If EEE is suspected in a person, it should be reported to MDHHS at 517-335-8165.

    In late summer and autumn of 2020, Michigan experienced an outbreak of EEE.  EEE is one of the most dangerous mosquito-borne diseases in the United States, with a 33 percent fatality rate in people who become ill.  In 2020 there were 4 human cases (including two deaths), and 41 animal cases in Michigan.  In an effort to prevent spread of Eastern Equine Encephalitis (EEE), MDHHS conducted aerial mosquito control treatment Sep. 16 - 23, 2020 in certain high-risk areas of Michigan.  This treatment was completed successfully and there were no adverse events reported from the aerial treatment. 

  • EEE 2020

    2021 Press Releases

    Eastern Equine Encephalitis Continues to Pose a Threat to Michiganders and Their Animals (10/12/2021)

    First Mosquitos of 2021 carrying Eastern Equine Encephalitis virus found in Barry County (8/27/2021)

    State Confirms Eastern Equine Encephalitis in Livingston County Horse (8/26/2021)

    FAQ :  Eastern Equine Encephalitis and Aerial Treatment 

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    Past MDHHS Press Releases


    Arbovirus Update, including Eastern Equine Encephalitis in Michigan (Updated January 20, 2022):

    2020 Weekly Arbovirus Surveillance Summary