Texas and New Mexico health departments said on Friday that the number of measles cases in their states rose 20% since their last reports three days ago, as experts warn they expect the outbreak to further spread in coming weeks.

A measles outbreak in Kansas has more than doubled to nearly two dozen cases over the last week, according to state health officials, who said they identified a “possible link” between confirmed cases of the highly contagious illness and a larger outbreak in Texas and New Mexico.

Texas' outbreak began two months ago. State health officials said Friday there were 73 new cases of measles since Tuesday, bringing the total to 400 across 17 counties — most in West Texas. Forty-one people have been hospitalized since the outbreak began, and Andrews and Midland counties were new to the list.