Past Outbreaks in Wisconsin

Stack of folders full of paper documents

Archived outbreaks and investigations

Below is a list of past outbreaks and investigations with wide impact in Wisconsin.

For current outbreaks and investigations, visit our Outbreaks in Wisconsin page.

2024 Outbreaks

2023 Outbreaks

2022 Outbreaks

2021 Outbreaks

2020 Outbreaks

2019 Outbreaks

Last revised April 4, 2025