Measles cases in the United States have climbed past 4,000 this year, reaching a record level, the Centers for Disease Control and Prevention said Friday.
The CDC reported 4,080 confirmed cases nationwide as of Thursday.
That figure has already eclipsed the 2,289 cases recorded in all of 2025, which marked the highest annual total in the U.S. in 30 years.
Cases have been reported in most states, as well as Washington, D.C., underscoring the broad reach of the highly contagious disease.
Pennsylvania crossed the 1,000-case threshold this week after health officials announced 145 additional infections Wednesday.
The Pennsylvania Health Department said five deaths in the state this year have been associated with measles. Under the state’s definition, a death is considered measles-associated when it occurs within 30 days of symptom onset, clinical evidence indicates an infection, and laboratory testing is positive—provided the death was not caused by an unrelated event, such as a car crash.
In neighboring New York, Gov. Kathy Hochul declared an emergency Monday as measles infections continued to rise in the region. An executive order issued by Hochul expands the number of health professionals authorized to administer measles vaccines and permits nurses to order testing, her office said.
Nationwide, 95% of measles patients reported this year were either unvaccinated or had an unknown vaccination history, according to the CDC. Roughly 2% had received one dose of the measles, mumps and rubella vaccine, while another 2% had received both recommended doses.
The first signs of measles generally develop one to two weeks after exposure, the CDC said. Symptoms often begin with a high fever, cough, runny nose and red, watery eyes.
Small white spots can appear inside the mouth two to three days later. A measles rash typically follows within three to five days after the initial symptoms begin.
