DARLINGTON — The number of active cases in the latest measles outbreak continues to rise. Wisconsin now has 159 confirmed cases in 2026, with 157 active — all of which in Lafayette, Iowa and Grant counties. Of the 159 total confirmed cases, 158 are unvaccinated people. Five cases have now resulted in hospitalization.

The rate of active cases by age has changed little, with 59.1% children between 0-17 years old. Of that, 45.9% (73 total) are children between 5-17 years, while 13.2% (21 cases) are children between 0-4 years of age.

As of Tuesday, Sept. 8, Lafayette County leads the state with 77 active confirmed cases, up 12 from the previous update on Friday, Sept. 4. Iowa County has 62 cases, and Grant County has 18 cases. Dane County and Waukesha County had one case each back in January 2026.

Measles symptoms start showing between 10-21 days after getting infected. Measles is one of the most contagious diseases. The virus easily spreads from person to person. It can spread through coughing and sneezing. People who are infected can spread measles to others four days before, and up to four days after, the rash appears. The measles virus can stay in the air for up to two hours after a sick person coughs or sneezes.

You can get measles by breathing contaminated air or touching an infected surface, and then touching your eyes, nose, or mouth. That means you can catch measles nearly anywhere, such as the grocery store, movie theaters, or on a bus or plane. A Measles, Mumps and Rubella (MMR) vaccine is your best protection. Two doses of the vaccine are about 97% effective at preventing measles.