Government health officials say there have been 971 cases of measles in the United States so far this year, the most cases since 1994, when there were 963 cases for the entire year.
The Centers for Disease Control and Prevention said Thursday if current outbreaks in and around New York City continue into the fall, the United States could lose its status as a country that has eliminated measles.
"That loss would be a huge blow for the nation and erase the hard work done by all levels of public health," a CDC statement said.
Measles was declared eliminated in the U.S. in 2000, and the CDC says one of the primary reasons is the availability and widespread use of a safe and effective vaccine.