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Eastern Equine Encephalitis: Wisconsin Data

The first human case of Eastern equine encephalitis (EEE) in Wisconsin was identified in 1964.

EEE is very rare in Wisconsin, but can lead to severe illness or even death. There have been six reported human cases of EEE in Wisconsin from 1964 to 2021.

Two of those cases occurred in 2020, and one in 2021.

This page includes statewide data for EEE.

Counties with reported cases of EEE in horses or in humans indicate that some mosquitoes in the area are infected with the virus and may spread EEE to other humans or animals.

For information on national data, visit the Centers for Disease Control (CDC) Epidemiology and Geographic Distribution page for Eastern Equine Encephalitis.

Eastern Equine Encephalitis virus case data

2022 Wisconsin EEE Case Data
Updated October 7, 2022

Human confirmed 1
Human probable* 0
Deaths** 0
Hospitalizations 1
Equine (horse) 0
Counties reporting EEE activity 1

* Probable cases have presumptive positive laboratory results without confirmatory testing at CDC.
** The deaths are included among the confirmed and probable cases.

Human Eastern Equine Encephalitis data (2011-2021)

Questions about illnesses spread by mosquitoes? Contact us!
Phone: 608-267-9003 | Fax: 608-261-4976

Last revised October 10, 2022