West Texas is in the middle of a still-growing measles outbreak with 505 cases reported on Tuesday. The state expanded the number of counties in the outbreak area this week to 10. The highly contagious virus began to spread in late January and health officials say it has spread to New Mexico, Oklahoma, Kansas and Mexico.

At least six children at a day care in Lubbock, Texas, tested positive for measles amid the state's growing outbreak, local officials confirmed to CBS News Tuesday. On Monday, Lubbock Public Health issued immunization recommendations for the whole county following the cases at Tiny Tots U Learning Academy on South University Avenue.

The Texas Department of State Health Services (DSHS) reported 505 cases in the ongoing measles outbreak as of Tuesday, April 8. DSHS said 57 patients were hospitalized.