A growing number of Central Texas health departments are warning residents of possible exposure to measles, the latest sign that the outbreak in West Texas is spreading across the state. Why it matters: Measles is a highly contagious and potentially life-threatening disease that has surged in areas with high vaccination exemption rates.

Officials say an individual who tested positive for the virus in West Texas traveled to two major universities and one of the nation's busiest tourist attractions — the San Antonio River Walk.

Confirmed measles cases in Texas have reached at least 90, making this the worst measles outbreak in 30 years. Experts warn the number of Texas cases is likely much higher.