Measles is spreading across the U.S., with an outbreak growing in Texas and cases reported in nearby states. Experts explain whether or not you should be concerned.

An outbreak of measles in the South Plains of Texas is continuing to grow, with the number of cases doubling in less than a week. At least 48 cases were identified with symptom onset within the last three weeks, according to the Texas Department of State Health Services. More than a dozen people were hospitalized.