U.S. measles count keeps climbing as outbreaks persist in three states

The nationwide measles count has kept climbing through the summer, with federal health officials confirming more than 2,700 confirmed cases so far this year across 32 states and New York City. The total has already left last year's count, which was itself the highest in more than three decades, far behind.

How big the outbreaks have grown

A single outbreak that began last October in Spartanburg County, South Carolina, grew into the largest the country has seen in decades, swelling to nearly 1,000 cases before finally tapering off in the spring. Utah's outbreak has since become the largest still active, with more than 500 cases confirmed there this year alone. In recent weeks, Pennsylvania has emerged as a new hot spot, with dozens of new cases confirmed there in a single week, while Arizona has reported a cluster tied to a business in Maricopa County that health officials called far outside the norm for a county that typically sees about one case a year.

The Centers for Disease Control and Prevention says 94% of this year's confirmed cases are tied to one of roughly three dozen identified outbreaks rather than isolated, unconnected infections, a pattern consistent with the virus moving through specific communities with lower vaccination coverage rather than spreading broadly through the general population.

Where cases are concentrated now

Beyond South Carolina, Utah, Pennsylvania and Arizona, smaller but notable clusters have also been tracked in Washington state, Florida and Texas, including cases linked to a federal immigration detention facility earlier in the year. Roughly a quarter of this year's cases have been in children younger than five, and the large majority have been in children and young adults under 20.

Vaccination gaps behind the spread

More than 90% of this year's patients were unvaccinated or had an unknown vaccination status. Only a small number of states have kept kindergarten vaccination coverage above the roughly 95% threshold generally considered necessary to prevent sustained spread, and public health researchers say that gap remains the single biggest driver of the outbreaks. About 7% of this year's patients have required hospitalization, a lower share than last year's 11%, and no measles deaths have been reported so far in 2026, after three deaths, including two children, were recorded last year.

A review of the country's elimination status

The scale of this year's spread has put the country's measles elimination status, held since 2000, under formal review. The Pan American Health Organization's regional verification commission is set to evaluate later this fall whether measles has been circulating continuously in the United States for more than twelve months, the technical threshold for losing elimination status. Canada lost its own elimination status last November after a similar review found sustained transmission stretching back more than a year. Public health researchers say losing the designation would carry no direct penalty or funding change, but would mark a symbolic acknowledgment that the country's vaccination safety net has weakened. Officials continue to recommend the standard two-dose vaccination series, which is roughly 97% effective at preventing infection, as the most effective way to bring the outbreaks to an end.