Measles cases linked to a West Texas outbreak have now been confirmed in two North Texas counties, marking the virus's continued spread across the state. State health officials said cases have been identified in Collin and Rockwall counties,

The two cases were confirmed as part of the outbreak by the Texas Department of State Health Services on Tuesday.

There’s been a second straight single-digit increase in new measles cases tied to the West Texas outbreak, but the state health department also says three new counties reported one case each. Two of the three new counties are just north of Dallas.