CDC to develop measles-death definition amid Pennsylvania outbreak, highest nationwide case surge in decades

What This is

• The CDC has reported thousands of confirmed measles cases in 2026, with totals above 3,100 and described as the highest annual count in decades.
• Pennsylvania has reported a large statewide outbreak, with about 731 confirmed cases across 38 counties and many hospitalizations.
• Pennsylvania officials say four unvaccinated people died in cases linked to measles, but the CDC has not added those deaths to its national measles tally while it reviews them.
• The CDC is working with the Council of State and Territorial Epidemiologists to create a standardized definition for measles deaths as the outbreak grows.
• The CDC has shifted how it counts measles deaths, relying more on National Center for Health Statistics mortality data rather than state reports, drawing scrutiny during the Pennsylvania dispute.
• Lancaster County’s coroner said one infant death was caused by measles and another infant death listed measles as a contributing condition, while the CDC has not said whether it will count them as measles deaths.
• Pennsylvania asked the CDC for emergency outbreak support (Epi-Aid) but said it would withdraw the request unless the CDC publicly recognizes the four measles-associated deaths.

Why This Matters

• Clear, trusted death reporting shapes how people judge risk and decide whether to vaccinate, especially during a fast-moving outbreak.
• If state and federal health agencies publicly clash, people may doubt guidance even when it is urgent and practical.
• How deaths are counted can shift where emergency staff, funding, and attention go during an outbreak.
• The dispute feeds wider fears that politics can influence what health data the public sees.