Wisconsin nears 200 measles cases as outbreak concentrates in southwest counties

# What happened

Wisconsin's measles outbreak continued to expand. The Wisconsin Department of Health Services (DHS) reported 192 confirmed measles cases in 2026 as of September 25, 2026. Most of those infections are concentrated in the southwestern corner of the state.

# Where cases are concentrated

The outbreak is focused in four counties: Grant, Iowa, Lafayette, and Vernon. DHS reported 180 confirmed and six probable cases in that cluster. The department says the investigation indicates measles is spreading locally in those counties, and local health departments are working with DHS to identify and notify people who may have been exposed.

# Cases outside the southwest cluster

DHS also confirmed measles cases in Marathon County and Chippewa County. Those cases were tied to out-of-state travel, and DHS said they are not related to the southwest outbreak. DHS has not disclosed travel destinations or travel-related details for those cases.

# Public health response

Public health agencies are taking several actions:

• Monitoring reports of illness and conducting enhanced surveillance in outbreak areas.
• Working with health care and community partners to identify and notify possible exposures.
• Providing access to vaccines and monitoring for potential public exposures to measles.

DHS noted that not everyone who tests positive for measles gets sick, seeks medical care, or contacts public health agencies, which can complicate counting and response efforts.

# Vaccination message and data point

DHS's primary advice is to get vaccinated against measles. The department reported that one in four people who will test positive for measles is unvaccinated. The Centers for Disease Control and Prevention (CDC) reported broader national figures: 3,659 confirmed measles cases in 47 states or jurisdictions and 40 new outbreaks this year. DHS and federal officials have not publicly identified where outbreaks originated or released names of people who have become ill.

# Practical implications for residents

For residents elsewhere in Wisconsin, the presence of travel-linked cases in Marathon and Chippewa counties shows the outbreak is not strictly confined to one region. Travelers with symptoms consistent with measles should contact health authorities before seeking care so clinics can take appropriate infection-control steps.

# Bottom line

The outbreak remains concentrated in a defined southwest cluster but has produced travel-related cases elsewhere in the state. State health officials emphasize vaccination, enhanced surveillance, and active case-finding as their main response strategies.