Wisconsin Measles Hits 171 Cases as Virus Reaches Chippewa County

Wisconsin confirmed its 171st measles case of 2026 in Chippewa County, the third new county in a week, with 99% of cases in unvaccinated people.

Wisconsin health officials confirmed a new measles case in Chippewa County on September 22, pushing the state's 2026 total to 171 cases, according to WIZM. It is the third new county to report a measles case in the past week, joining Vernon and Marathon counties, on top of the more than 160 cases tied to the ongoing outbreak in Grant, Iowa, and Lafayette counties. According to Artvoice, state health officer Dr. Ryan Westergaard has called this the worst measles year in Wisconsin in more than 35 years. Officials said they are not aware of any public places where someone could have been unknowingly exposed to the Chippewa County resident, and they did not share how the case was acquired, per the Milwaukee Journal Sentinel.

The outbreak originated in southwestern Wisconsin in late July and climbed rapidly, peaking at 49 confirmed cases during the week of August 24, according to WIZM. Now the virus is breaching county boundaries. The Milwaukee Journal Sentinel reports that Stephanie Schauer, immunization program manager for the Wisconsin Department of Health Services, said one of the two Vernon County cases is likely linked to the cases circulating in the southwest. Artvoice reports the Chippewa County case is travel-related and not connected to the primary outbreak, but the pattern of new counties reporting cases in quick succession signals that measles, one of the world's most infectious diseases, is finding susceptible communities far from the original epicenter. The disease spreads through the air and can linger for up to two hours after an infected person coughs or sneezes.

The state's numbers tell a stark story about vaccination. According to the Wisconsin DHS dashboard data cited by WIZM, 170 of 171 cases — 99.4% — occurred in unvaccinated individuals. Five people, 2.9% of cases, have been hospitalized, and no deaths have been reported. The Sunday Guardian reports that only about 85% of Wisconsin kindergartners are fully vaccinated, well below the 95% threshold needed for community immunity. Nationally, the Centers for Disease Control and Prevention has confirmed more than 3,400 measles cases across the country in 2026, per the Milwaukee Journal Sentinel, a figure Artvoice places at 3,471 cases across 47 states — one of the worst domestic outbreaks in decades.

Measles is among the most contagious viruses known, and the Wisconsin Department of Health Services warns it can cause serious complications including pneumonia, brain damage, deafness, and sometimes death, according to TMJ4. Symptoms typically appear 10 to 21 days after exposure, starting with high fever, cough, runny nose, and red, watery eyes, followed a few days later by a rash that begins on the face near the hairline and spreads across the body; tiny white spots inside the mouth can also appear.

Health officials remain firm that vaccination is the only viable way to halt the spread. The MMR vaccine's effectiveness is well documented: two doses prevent measles infection 97% of the time, while one dose provides 93% protection, according to figures cited by Artvoice. The Wisconsin Department of Health Services urges all residents to verify their vaccination records immediately, and anyone experiencing symptoms is advised to avoid others and call a doctor's office or clinic before showing up in person, so staff can prepare and prevent further exposure. Officials are continuing contact tracing in affected counties, and updates are being tracked on the DHS Measles Dashboard and the state's Outbreaks and Investigations webpage, per WIZM.