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.

There is a measles outbreak in the South Plains region of Texas, with 58 confirmed cases, primarily in Gaines County, which accounts for 45 cases.

Texas reported 90 cases this week, while New Mexico reported nine. A majority of the cases have been in a Texas county where vaccination rates have lagged behind the rest of the state.