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.

The largest measles outbreak in decades has reached San Antonio and San Marcos. 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.

A warning has been issued for three Texas cities after someone with measles visited them while contagious. The Texas Department of State Health Services (DHSH) shared the warning on Monday "so unvaccinated people may monitor themselves for symptoms and seek testing if symptoms occur.

Two Texas universities and their surrounding communities have issued warnings about potential exposure to measles after giving campus tours to at least one person who tested positive for the virus.

The City of San Antonio is warning residents about a potential exposure to measles at UT San Antonio and the Riverwalk earlier this month.