The CDC has confirmed 1,723 measles cases as of Nov. 12 — a more than 500% increase from 2024, when 285 U.S. cases were confirmed.
The measles outbreak has progressively worsened. Nearly every state has reported measles cases, except for Connecticut, Delaware, Maine, Massachusetts, Mississippi, New Hampshire, North Carolina and West Virginia, according to the CDC.
Texas is home to the most acute outbreak, with 803 confirmed cases. Arizona and Montana follow with 124 and 100, respectively.
Here are five things to know:
1. Eighty-seven percent of confirmed measles cases this year are associated with one of the 45 outbreaks. In 2024, 69% of cases (198 of 285) were outbreak-associated.
2. Twelve percent of measles cases have been hospitalized, accounting for 206 of the 1,723 cases. About 1 in 5 measles patients younger than 5 have been hospitalized, as well as 11% of patients ages 20 or older and 6% of those between 5 and 19 years old.
3. Among the confirmed cases, 92% are either unvaccinated or have an unknown vaccination status.
4. There have been three confirmed deaths from measles in 2025 so far.
5. The steady increase in measles cases coincides with the 2024-25 respiratory virus season, which is seeing early strains. Emergency department visits for respiratory syncytial virus have recently risen among children under 4, and a more-severe influenza strain has caused unusually early and severe outbreaks in Canada, the U.K. and Japan — drawing an uncertain picture of this virus season.
