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 measles outbreak in West Texas has topped 120 cases and resulted in the first U.S. death from the illness in a decade.

An unvaccinated child in west Texas died from measles this week, according to a Wednesday news release from the Texas Department of State Health Services. This is the first death from the west Texas measles outbreak that began late last month, and is the first death from measles in the United States since 2015.

The first person known to have died from measles in the U.S. in a decade was announced by health officials on Wednesday and described as a "school-aged child" who perished in a children's hospital in West Texas,

The measles outbreak in Texas has grown to 124 cases mostly in children and in those who are unvaccinated, according to state data published Tuesday.