Wisconsin health officials said Thursday that an infant died of measles, the state's first measles-associated death since 1990, during an outbreak that has confirmed hundreds of cases this year^1,2.

The Division of Public Health in the Department of Health Services said a coroner listed measles as the immediate cause of death². Health Secretary Kirsten Johnson said any child's death is a tragedy, "even more so when it is related to a vaccine-preventable disease"^1,2.

As of Thursday, Wisconsin had confirmed 431 measles cases and nine related hospitalizations, Ars Technica reported more than 430 cases across 13 counties^1,2. Most cases have been concentrated in the state's southwest, KHON2 reported, citing The Hill².

DPH said 79.8 percent of children had received one or more MMR doses by 24 months of age². Vernon County's 24-month coverage was 42.3 percent in 2025, with neighboring Crawford, Richland and Monroe counties in the 60-percent range, according to that report².

The Wisconsin death was the third measles fatality reported nationally this week after a New York child's death Monday and a Pennsylvania death Wednesday, Ars Technica reported¹. Pennsylvania has an ongoing outbreak with 1,467 cases this year, that account said¹.

Ars Technica counted nine reported U.S. measles deaths this year, eight confirmed by state officials, including the Wisconsin infant, the New York child and seven Pennsylvania deaths, six of them confirmed¹. The CDC was reporting four measles deaths and 5,182 cases across 47 states and jurisdictions as of Nov. 5¹. CDC data had not yet matched state-reported death totals, KHON2 reported².

Ars Technica reported that the CDC changed how it counts measles deaths, moving from state-confirmed deaths to federal death records that take longer to process¹. The same account said a PAHO infectious-disease committee is scheduled Nov. 10-13 to review 2025 and early 2026 data on whether measles has reestablished in the United States, which declared measles eliminated in 2000¹.

Wisconsin officials noted that not everyone who becomes ill seeks care or testing, so cases may go unreported¹. Officials did not publicly identify the infant or give further clinical details in the accounts reviewed^1,2.