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, nine horses, one deer, and one bird 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.
2021 Press Releases
Arbovirus Update, including Eastern Equine Encephalitis in Michigan (Updated November 22, 2021):