The ongoing measles outbreak in West Texas has doubled in size to 48 cases. It's the state's worst in nearly 30 years.

An outbreak of measles has spread to 48 cases across four counties in the South Plains region of northwestern Texas, doubling in scope from earlier this week, health officials said. Most of the cases are in school-aged children,

Public health authorities said Tuesday that an outbreak of measles in western Texas has expanded, while a new case was confirmed nearby across state lines in New Mexico