The US Centers for Disease Control and Prevention confirmed one measles-related death in the country in 2026, according to the agency’s website on Wednesday.

The CDC added the figure is subject to change and will be updated as additional information becomes available and relevant reviews are completed.

Pennsylvania has reported four measles-associated deaths in 2026 so far, according to the state’s health department, but the CDC did not confirm whether its reported measles-related death was among those cases.

A U.S. Department of Health and Human Services spokesperson told Reuters that the National Center for Health Statistics had notified the agency of a death reported by a state.

The US has recorded 3,471 measles cases this year as of September 17, according to the CDC’s data.

The agency said last week it is working with the Council of State and Territorial Epidemiologists to develop a standardized case definition for measles deaths, as the outbreak grows across the country.

This work is intended to promote consistent classification and reporting of measles deaths across jurisdictions, HHS said.

(Reporting by Siddhi Mahatole and Christy Santhosh in Bengaluru; Editing by Vijay Kishore)