Vaccination Is The Most Important Step People Can Take

An expanding measles outbreak in Wisconsin underscores the need for vaccination, awareness around symptoms and preventing the spread of the disease, health experts at ThedaCare said.

As of Sept. 22, the Wisconsin Department of Health Services said the state had seen more than 170 cases of measles so far this year. According to health officials, the vast majority of those cases were in unvaccinated individuals. It’s the highest number of cases in the state in decades.

“Getting the MMR vaccine is the most effective way to help prevent contracting and spreading measles,” said Angela Divjak, MD, a family medicine physician with ThedaCare Physicians-Shawano. “With the number of cases continuing to increase, it’s also important to know what to do if you’re exposed to measles or develop symptoms. Because of how easily measles spreads, isolating from others is critical.”

Outbreak Details

Most of Wisconsin’s measles cases in 2026 have been concentrated in southwestern Wisconsin, particularly in Grant, Iowa and Lafayette counties. Cases have also been reported elsewhere in the state, including Vernon and Marathon counties. More recently, a measles case was also reported in Chippewa County.

The MMR vaccination rate for Wisconsin kindergarteners was 85.1% for the 2025-26 school year. That’s nearly 10% shy of the national target of 95%.

Wisconsin has the third-lowest MMR vaccination rate in the United States, according to the Centers for Disease Control and Prevention. In the area ThedaCare serves, Marquette and Green Lake counties have the lowest rates of MMR vaccination for kindergartners, both at 68% according to Wisconsin DHS.

To date in 2026, the United States has confirmed more than 3,470 measles cases, up from 2,287 in 2025 and 283 in 2024.

What is Measles?

Measles is a contagious disease caused by a virus. A person with measles may infect up to 90% of unvaccinated people with whom they come into close contact, according to the CDC. Measles can live for up to two hours in an airspace after an infected person leaves an area.

The CDC provides the following measles vaccination recommendations:

• Children need two MMR doses: one at 12-15 months and a second at 4-6 years.
• Older children, adolescents and adults need one or two doses of MMR vaccine if they don’t have evidence of immunity.
• Anyone traveling internationally should be fully vaccinated before departing.

The MMR vaccine begins providing protection about two weeks after a person receives it.

Symptoms of Measles

Measles spreads through the air when an infected person breathes, coughs or sneezes. It can also spread through direct contact with infectious respiratory droplets. Symptoms generally develop seven to 14 days after exposure and tend to appear in stages, according to the CDC.

7-14 days after exposure: early symptoms

• High fever, which may rise above 104°F
• Cough
• Runny nose
• Red, watery eyes, also known as conjunctivitis or pink eye

2-3 days after symptoms begin: Koplik spots

Tiny white spots, called Koplik spots, may develop inside the mouth.

3-5 days after symptoms begin: rash

• A measles rash usually starts as flat, red spots on the face near the hairline and spreads downward to the neck, torso, arms, legs and feet.
• Small, raised bumps may develop on top of the flat red spots.
• The spots may merge as the rash spreads across the body.
• Fever may spike to more than 104°F when the rash appears.

Measles may cause severe health complications, including pneumonia, encephalitis (brain inflammation) and death. Nationally, about one in five unvaccinated people who get measles are hospitalized.

“Because measles is highly contagious, it’s important to call the clinic or hospital before coming in for evaluation,” Dr. Divjak said. “ThedaCare also offers virtual care.”

“I can’t stress enough that vaccination is the most important step you can take,” she said. “Prevention is key. Beyond home comfort measures, supportive care and steps to prevent complications, there’s no specific treatment available for measles once it occurs.”

People interested in scheduling an MMR vaccination are encouraged to call the Vaccine Clinic Line at 920-702-6380 or schedule online. Vaccinations also are available at selected retail pharmacy locations for those ages 6 and older.

About ThedaCare

For more than 115 years, ThedaCare® has been improving the health and well-being of the communities it serves in northeast and central Wisconsin. The organization delivers care to more than 650,000 residents in 17 counties, and employs approximately 7,000 providers and team members at 180 points of care, including 10 hospitals. As an organization committed to being a leader in Population Health, team members are dedicated to empowering people to live their unique, best lives. ThedaCare is a not-for-profit health system with a level II trauma center, comprehensive cancer treatment, stroke and cardiac programs, as well as primary care. ThedaCare also partners with communities to understand needs, find solutions together, and encourage health awareness and action. ThedaCare is part of Froedtert ThedaCare, Wisconsin’s most comprehensive healthcare system.

For more information, visit thedacare.org or follow ThedaCare on social media.

Date posted: September 28, 2026