The country’s worst measles outbreak in over 25 years has spread to two more states in the past week, according to the Centers for Disease Control and Prevention.

There have been 41 new cases of measles in the past week, bringing the total to 1,022 cases as of June 6. For the first time in the current outbreak, cases of measles were confirmed in Virginia and Idaho. There are now confirmed cases in 28 states across the country.

The current outbreak through the first five months of this year is already the worst since 1992, and federal health officials have warned the country is at risk of losing its measles elimination status after the measles was declared eliminated in the U.S. in 2000.

Read more at The Hill.