The United States has registered its first death from measles since 2015, after a child who wasn’t vaccinated died in an outbreak in rural West Texas. Normally, most US cases are brought into the country by people who have travelled overseas.

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.

At least 124 cases have been reported since late January, mostly among children and teenagers who were unvaccinated or whose vaccination status was unknown.