The United States is facing its worst measles outbreak in years, with confirmed cases topping 4,000 across 45 states and Washington, D.C., according to data updated Friday by the Centers for Disease Control and Prevention.
The CDC now counts 4,080 confirmed measles cases as of October 8 — an increase of 193 in a single week. Among those, between 18 and 26 cases involved international visitors. About 414 patients, roughly 10 percent of cases, have required hospitalization.
Children and teenagers make up the largest share of infections. About 95 percent of cases are among people who are unvaccinated or whose vaccination status is unknown, according to the CDC.
Pennsylvania is the hardest-hit state, with 1,136 cases and 219 hospitalizations. The CDC has confirmed two measles-associated deaths nationwide in 2026, though Pennsylvania officials separately report five linked deaths in the state, according to reports.
The surge has triggered emergency action. New York declared a statewide disaster emergency on October 5 over its own outbreak, which has reached 108 cases, according to reports. Health officials are urging anyone not vaccinated against measles to get the shot as the virus continues to spread.
