Measles Outbreak in Southwest Wisconsin Continues to Grow

Tuesday, September 1st, 2026 -- 12:00 PM

(WPR Staff, Wisconsin Public Radio) The measles outbreak in southwest Wisconsin is continuing to grow.

According to WPR staff, the Wisconsin Department of Health Services said today it confirmed 22 additional cases this week. State data show there are now 98 reported cases in Grant, Iowa and Lafayette counties.

Those data include six cases listed as probable. All but three are in Iowa and Lafayette counties. All but one of the reported cases are in people who are unvaccinated. Most of those affected are children.

The number of cases has grown quickly since the first two were reported by DHS on Aug. 11. But state officials have said the illness has been concentrated in communities with low vaccination rates.

DHS says transmission of the highly contagious virus has been in people connected with previously identified cases. The department said the increasing number of people infected does not “necessarily indicate an increase in exposure risk to the broader public.”

Measles is highly contagious and can be spread through the air. The virus can even stay in the air for hours after a sick person coughs or sneezes. The disease can cause serious health complications including pneumonia and brain damage, and can be deadly.

The outbreak comes as new data from the U.S. Centers for Disease Control and Prevention showed Wisconsin had low measles vaccination rates for kindergarten students.

An estimated 85.1 percent of kindergarten students in Wisconsin had MMR vaccine coverage during the 2025-2026 school year, according to the CDC data.

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