The number of measles cases in the U.S. has risen to over 1,000 cases, according to new data from the Centers for Disease Control and Prevention (CDC) on Friday. 

As of May 15, a total of 1,024 cases were reported across 31 states amid the deadliest outbreak in years. Per the CDC, 96 percent of individuals with confirmed cases are either unvaccinated or have an unknown vaccination status.

Thirteen percent of individuals have been hospitalized, and there have been three confirmed deaths due to the disease this year, according to the data. 

Texas has made headlines in recent months due to its measles outbreak, with 718 confirmed cases as of May 13. The Lone Star State has the largest share of the country’s cases. 

Other states impacted by the outbreak include Alaska, Arkansas, California, Colorado, Florida, Georgia, Hawaii, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Missouri, Montana, New Jersey, New Mexico, New York City, New York State, North Dakota, Ohio, Oklahoma, Pennsylvania, Rhode Island, Tennessee, Vermont, Virginia, and Washington

Measles was officially declared an “eliminated” disease from the U.S. over 25 years ago. But this designation could be in peril if this current outbreak lasts over a year.