As of May 5, 2025, the United States is experiencing its most severe measles outbreak in over two decades, with Texas and New Mexico at the epicenter.​ Current Case Counts and Impact Origin and Spread The outbreak began in January 2025 within a close-knit Mennonite community in Gaines County,

There have been 935 confirmed cases of measles across nearly 30 states so far this year, according to the latest update from the CDC on Friday, an increase of 51 over the previous week and far surpassing the 285 measles cases reported in the entirety of 2024 (the CDC does not provide data on how many cases are actively infectious).

Texas’ measles outbreak has grown to 702 cases across 29 counties, according to a Tuesday update from the state public health department. The Texas Department of State Health Services estimates that less than 1% of those cases — or fewer than 10 of the reported cases — are “actively infectious.