Six young children at a Texas day care center have tested positive for measles — a dreaded scenario with the potential to accelerate an already out-of-control outbreak.

The measles outbreak in western Texas has hit 481 cases as 59 newly identified infections were confirmed over the last three days, according to new data published Friday.

Already, the U.S. has more measles cases this year than in all of 2024, the U.S. Centers for Disease Control and Prevention has said. Other states with outbreaks — defined as three or more cases — include New Mexico, Kansas, Ohio and Oklahoma. Since February, two unvaccinated people have died from measles-related causes.