Twenty-five years after the disease was declared “eliminated” in the U.S., cases are rising again, with a Texas outbreak now spreading to New Mexico. Measles cases continue to rise in the United States nearly two and a half decades after the virus had been declared eliminated in the country.

The number of people with measles in Texas increased to 146 in an outbreak that led this week to the death of an unvaccinated school-aged child, health officials said Friday.

Measles is a highly contagious, infectious disease that can spread easily among people who have not been vaccinated.