Eastern Equine Encephalitis

  • EEE Outbreak Information

    In late summer and autumn of 2020, Michigan experienced an outbreak of Eastern Equine Encephalitis (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 in certain high-risk areas of Michigan.  This treatment was completed successfully and there were no adverse events reported from the aerial treatment. 

    So far in 2021, one horse and one deer from Livingston County and one pool of mosquitos from Barry County have tested positive for EEE.  Monitoring will continue through the remainder of the summer and fall.  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.

  • EEE 2020

    2021 Press Release: State Confirms Eastern Equine Encephalitis in Livingston County Horse

    FAQ :  Eastern Equine Encephalitis and Aerial Treatment 

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    2020 Press Releases


    Arbovirus Weekly Update, including Eastern Equine Encephalitis in Michigan (Updated September 23, 2021):

    2020 Weekly Arbovirus Surveillance Summary