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.

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

A Northwest Texas resident who has tested positive for measles potentially exposed University of Texas at San Antonio students and other residents while visiting San Antonio earlier this month. The San Antonio Metropolitan Health District said the Gaines County resident tested positive for the virus and traveled to multiple locations here on Feb.