At least 124 cases of measles have been identified in Texas since late January, mostly among children and teenagers who are either unvaccinated or whose vaccination status is unknown, officials say.

A child in West Texas has died of measles, state health officials said on Wednesday, the first reported U.S. death from the highly contagious disease in a decade, as a Texas outbreak has grown from a handful of cases to more than 130 across two states.

Measles cases has risen to 124 across several counties in West Texas, and health officials are seeing no clear end in sight to the outbreak. Texas Department of State Health Services confirmed the first death related to the outbreak Wednesday.