Texas faces its worst measles outbreak in over 30 years, with the first US measles death since 2015, prompting calls for action from Democratic leaders.

The update from South Texas came just as the state health officials reported the first death from measles on Wednesday. In a statement, health officials said it was a 'school-aged child who was not vaccinated was hospitalized in Lubbock last week and tested positive for measles.

State records show 26 Bexar County school systems have measles vaccination rates below the 95% required for herd immunity. Most are private schools and charter schools.