The United States recorded 971 cases of measles in the first five months of 2019, surpassing the total for any year since 1992.
The United States declared measles eradicated from the country in 2000, but officials with the U.S. Centers for Disease Control and Prevention warned on Thursday that the country risks losing its measles elimination status.
There were a total of 2,126 U.S. cases of measles in 1992, the CDC said in a statement.
The disease has spread mostly among school-age children whose parents declined to get them vaccinated.
Public health officials blame the resurgence on the spread of misinformation about vaccines.