This year is the worst for measles spread in the U.S. since 1991. The news comes as Missouri has become the 18th state with an outbreak in 2025.

Already in 2025, the United States has reported more measles cases than in any full year since the early '90s, according to federal data. And that record-setting case count has been driven by a massive outbreak that began in Texas.

Johns Hopkins University data reflects the public health reversal in defeating the vaccine-preventable disease since measles was officially eliminated from the U.S. in 2000.