U.S. Measles Cases Top 4,080, Highest Since 1991, as Pennsylvania Outbreak Surges

ATLANTA, Oct. 11 (TodayViralUSA) — Confirmed U.S. measles cases have climbed to 4,080, the highest annual total since 1991, after another week of triple-digit increases driven largely by a stubborn outbreak in Pennsylvania, the Centers for Disease Control and Prevention reported.

The CDC’s latest update added 194 cases in a single week — the ninth consecutive week of double-digit gains — putting the country on pace to more than double last year’s 2,289 cases with roughly three months still left in 2026. Measles was declared eliminated in the United States in 2000 but has resurged amid falling MMR vaccination coverage.

Ninety-six percent of this year’s cases are linked to outbreaks, and nearly all were acquired domestically. Only 18 cases have been tied to international travel. Of the 4,080 patients, 17% are children under 5 and 42% are age 19 or younger. About 10% have been hospitalized. Ninety-five percent were unvaccinated or had unknown vaccination status.

Pennsylvania remains the epicenter

Pennsylvania now accounts for more than a quarter of the national total, with 1,136 confirmed cases — including 157 in the past seven days — according to the state health department. Ninety-nine percent of those patients were unvaccinated, and the hospitalization rate is 19%. Lancaster County leads with 415 cases, followed by Mifflin County with 167.

State officials said more than 56,000 MMR doses were administered in Pennsylvania in September, more than double a typical month. “The best protection against measles remains getting fully vaccinated,” the department said. Two doses of MMR are about 97% effective at preventing measles.

Pennsylvania has identified five measles-associated deaths involving two infants and three adults, while the CDC’s national tally still lists two deaths as the agency works with state epidemiologists on a standardized case definition. Experts note that measles typically kills one to three people per 1,000 infections, suggesting undercounted severity if deaths are rising.

Other states and federal response

Wisconsin has reported 263 cases, Ohio 231, New York 102 after declaring a state health emergency, and Kentucky 104. The CDC has sent about $100 million to states in recent weeks for immunization drives and surveillance, the New York Times reported, including multimillion-dollar packages for Minnesota.

CDC Director Erica Schwartz said at a Wall Street Journal event that the MMR vaccine is “absolutely safe, absolutely effective” and that parents should prioritize it. She linked the resurgence to herd-immunity gaps where coverage has fallen below the roughly 95% threshold needed to stop community spread.

Public-health officials warn that with school-year transmission still underway, weekly case counts may remain elevated unless vaccination catch-up campaigns close local immunity gaps.