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.

The measles outbreak that began in the South Plains region surged to 400 cases across Texas on Friday, with dozens more reported in New Mexico and Oklahoma. The latest update from the Texas Department of State Health Services added 73 infections,

Texas has reached 400 cases of measles in an outbreak that started two months ago. Texas, New Mexico, Ohio, Kansas and Oklahoma all have active measles outbreaks.