Measles Cases Reported Across Wisconsin Counties
State health officials have confirmed 164 measles cases as outbreaks continue to impact local communities.
Updated on Sept. 18, 2026 in Allergies
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Wisconsin has recorded 164 total measles cases through September 15, with two recent infections identified in Vernon County. While no new cases were reported in Marathon County as of September 18, the state continues to manage ongoing outbreaks.
Why it matters
The high number of cases among unvaccinated individuals underscores the importance of maintaining up-to-date immunization records to prevent further spread of the highly contagious virus.
Official state data shows 163 of the 164 recorded measles cases involved unvaccinated individuals, and there have been five measles-linked hospitalizations. The virus is known to remain in the air for up to 2 hours after an infected person has left a room.
The players
Wisconsin State Lab of Hygiene
This facility provides essential diagnostic testing and clinical reference services to support public health initiatives throughout the state of Wisconsin.
Wisconsin Immunization Registry
This is a confidential, population-based information system that tracks immunization records for residents across the state.
The details
The Wisconsin State Lab of Hygiene confirmed that a Marathon County resident contracted measles following travel out of state. Officials are monitoring the situation closely as cases have also been documented in other regions, including Grant, Iowa, and Lafayette counties.
Timeline
164 measles cases were recorded statewide through September 15, 2026.
Vernon County reported two new measles cases on September 16, 2026.
Marathon County reported no new measles cases as of September 18, 2026.
Health Landscape
This outbreak represents a significant departure from the CDC measles elimination criteria, which historically kept the state free of sustained transmission. The recent surge challenges previous public health milestones as medical professionals work to curb current transmission patterns.
Residents should verify their vaccination status immediately by accessing the Wisconsin Immunization Registry to ensure they are protected. If you suspect exposure to the virus, contact your healthcare provider to discuss potential symptoms and necessary precautions.
The takeaway
Maintaining up-to-date vaccination records is the most effective way to prevent the spread of measles within your local community. Consult with a medical professional to ensure your family remains protected against vaccine-preventable diseases.
Further reading
For more information on monitoring public health, visit the Allergies section of our site.
More information
To check your status or update records, visit the Wisconsin Immunization Registry.
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Do you trust that current public health measures are sufficient to contain measles in your area?
