A measles outbreak in Texas has reached San Antonio, with 90 cases reported, mostly in children. Vaccination remains crucial to control the spread.

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.

University of Texas at San Antonio Main Campus from 10 a.m.-2 p.m. The Wax Museum, Ripley's Believe It or Not and Ripley's Illusion Lab along the River Walk from 2:30-5:30 p.m.

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.

Some private schools have shut down because of a rapidly escalating measles outbreak in West Texas. Local health departments are overstretched, pausing other important work as they race to limit the spread of this highly contagious virus.