The number of measles cases in the U.S. this year has hit its highest level in nearly three decades.
The Centers for Disease Control and Prevention said Thursday there have been 971 cases of measles reported so far in 2019. That's the most since 1992, when 963 cases were reported for the entire year. And there's still six months left in 2019.
Multiple states have reported cases of the highly contagious virus. But the greatest number of cases -- at least 750 of them -- have come from just two places — New York City and Rockland County, New York.
The CDC says those outbreaks have gone on for nearly eight months now. And if they continue through the summer and fall, it warns the U.S. could be forced to remove measles from the list of "eliminated" diseases.
The agency's director said in a statement: "Measles is preventable and the way to end this outbreak is to ensure that all children and adults who can get vaccinated, do get vaccinated."
The CDC says it's working with state and local health officials to eliminate ongoing outbreaks.