CDC Moves to Standardise Measles Death Reporting as Cases Climb
The CDC is developing a standard measles death definition as US cases rise to 3,471 and Pennsylvania reports four outbreak-linked fatalities.
The US Centers for Disease Control and Prevention is working with the Council of State and Territorial Epidemiologists to establish a standardised case definition for measles deaths, the agency said, as the country's outbreak continues to widen.
The CDC reported 3,471 confirmed measles cases nationwide as of September 17, an increase from 3,294 a week earlier. Its national tally records no deaths for 2026.
That figure diverges from state-level reporting. The Pennsylvania Department of Health this week confirmed two additional measles-associated deaths, both in unvaccinated people, raising the state's outbreak-linked total to four.
The CDC has not incorporated those deaths into its national count after switching to mortality data from the National Center for Health Statistics rather than relying on state health departments, a change that has attracted scrutiny.
On Thursday, Pennsylvania's health department requested emergency support from the CDC to address its outbreak, conditional on the agency recognising the four measles-associated deaths the state has reported.
The CDC said it would revise its reporting as further information and relevant reviews become available.
Separately, the Republican chairman of the US Senate health committee on Wednesday attributed recent measles deaths in Pennsylvania to the Trump administration's approach to vaccines.