US Measles Cases Reach 4,410 as CDC Sends Investigator to Pennsylvania
The CDC has recorded 4,410 measles cases across the United States in 2026, including 451 hospitalisations, and is deploying a federal disease investigator to Pennsylvania to help contain the country's hardest-hit state.
The United States Centers for Disease Control and Prevention has recorded 4,410 measles cases nationwide so far in 2026 — a rise of 330 in a single week — along with 451 related hospitalisations. Children and teenagers aged five to 19 account for 42 percent of all cases, adults 20 and older for 41 percent, and children under five for the remaining 17 percent.
Pennsylvania is the most severely affected state, reporting 1,222 cases across 42 counties as of Wednesday, including 86 new infections since October 9. The outbreak has caused 225 hospitalisations and five confirmed measles-associated deaths there; state officials are investigating a sixth reported death. At Pennsylvania's request for federal assistance — known as an Epi-Aid — the CDC is sending a so-called "disease detective" from its Epidemic Intelligence Service to work alongside state health officials.
To counter the spread, Pennsylvania health staff have given out more than 5,900 measles, mumps and rubella vaccine doses at 202 pop-up clinics since the outbreak began in late April.
On October 5, New York Governor Kathy Hochul declared a statewide disaster emergency in response to rising cases in neighbouring Pennsylvania. The order, in effect until November 4, broadens the range of healthcare professionals authorised to administer vaccines and gives nurses greater flexibility to order measles testing.
CDC data show measles vaccination coverage among US kindergarteners fell from 95.2 percent in the 2019–2020 school year to 92.4 percent in 2025–2026. The agency estimates roughly 280,000 kindergarteners are now at risk due to gaps in vaccination coverage.
