U.S. measles cases jumped by a third over the past week, according to Centers for Disease Control and Prevention data, a worrying sign in the outbreak that’s already linked to two deaths.

New Mexico’s health department listed Friday that an adult who had died and then tested positive for measles had succumbed to the disease, though the state’s medical examiner has yet to confirm the cause of death. If it was caused by measles, it would be New Mexico’s first such fatality in at least 40 years, according to the CDC.

U.S. cases since the beginning of the year rose by 58 to 222 across 12 states, the CDC reported Friday, and 38, or 17% of those confirmed cases, have led to hospitalization.

Texas, the hardest-hit state with the first U.S. reported death in a decade, reported 198 cases on Friday, 39 more than its last update on March 4. And New Mexico’s confirmed cases are now at 30, an increase of 20 from its prior report. All of New Mexico’s cases have been in Lea County, which abuts Gaines County, the epicenter in Texas.

The CDC’s weekly data lags behind each individual state’s count and only includes confirmed cases reported the Thursday before data is released, so does not include the Texas and New Mexico updates Friday. Not even three months into 2025, U.S. cases are already approaching last year’s total of 285.

Measles is a highly contagious disease — up to 90% of the people around a positive case who are not immune will become infected, according to the CDC. Texas has been the epicenter of the outbreak, and health officials there have said it is probably larger than what’s already reported.

“I don’t think it’s over. It’s a huge population out there,” said Philip Huang, director of Dallas County Health and Human Services. “There’s some question about how many people are actually getting tested, too, and are we always getting the full picture of what’s going on?”

Tracking an outbreak

A team of CDC experts is now in Texas after the Department of State Health Services requested federal help for tracking the outbreak on Feb. 28. Three CDC physicians with experience in infectious disease and four epidemiologists are split across the West Texas region where the outbreak is located, a spokesperson for the state’s health department said in an email.

The whole team is from the CDC’s viral vaccine preventable disease branch in the National Center for Immunization and Respiratory Diseases. So far, the CDC has provided 2,000 vaccines to the state, according to a person familiar with the matter.

The state has also brought on an extra 36 contractors to help with vaccination efforts and specimen collection.

Nearly one in five children are unvaccinated in Gaines County, Texas, the area hardest hit. The MMR vaccine is 93% effective in preventing infection after one dose and the best way to prevent the spread of the highly contagious disease, public health officials say.

U.S. Health and Human Services Secretary Robert F. Kennedy Jr. recently touted unconventional remedies, like vitamin A, in a Fox News interview, which concerned local health officials.

“We really cannot distract from or dilute the primary message that vaccination is the key to addressing this,” Dallas County’s Huang said

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With assistance from Lindsay Blakely and Bill Haubert.

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