At least 124 cases of measles have been reported in Texas since late January — marking the largest outbreak in the state in close to 30 years. The dozens of reported cases have mostly affected children,

Health authorities warned of further spread. Most U.S. measles cases this year involved people 19 and under and those without a confirmed vaccination.

A measles outbreak in the southwestern United States has infected nearly 100 people in recent weeks. The deadly illness has sickened dozens of people in west Texas and New Mexico since late January. The Texas Department of State Health Services confirmed 90 cases of measles,