That's about three times the usual number of cases of measles, CDC Director Thomas Frieden said Thursday. The USA has seen nine outbreaks this year, with the largest in New York, North Carolina and Texas.
More than 98% of measles patients were unvaccinated, Frieden said.
"This isn't the failure of a vaccine; it's the failure to vaccinate," Frieden said.
The USA's overall measles vaccination rate remains high.
In fact, measles has been officially eliminated throughout the Western Hemisphere. That means that measles, unlike the flu, no longer circulates among the general population.