Utah Is the New U.S. Hotspot for Measles

While South Carolina appears to be getting its measles outbreak under control, a new U.S. hotspot has popped up: Utah.

A cross-border outbreak between Utah and Arizona has persisted since last summer, but researchers are eyeing a state high school wrestling championship as a possible super-spreader event.

The state has also seen breakthrough infections among vaccinated clinicians, its department of health and human services (DHHS) said.

Utah had 46 new measles cases last week, the highest of any state, according to data from the Yale School of Public Health’s measles data tracking project. Its total now stands at 464 since the outbreak began in August 2025 and spread across the state’s border to Arizona, according to the Yale tracker.

A total of 41 people have been hospitalized with measles during the ongoing outbreak, according to publicly available DHHS data. Still more have presented to emergency departments, and about two-thirds of infections have been in kids.

“There’s been over 100 cases in the last 3 weeks,” U.S. Army Lieutenant Colonel Joanne McGovern (Ret.), who leads the Yale tracking project, told MedPage Today. “There’s definitely community spread going on.”

Clinicians feel they’re at the point where “you have to look up the exposures because there are so many potential exposure locations,” Ellie Brownstein, MD, a pediatrician in the Salt Lake City area and vice president of the Utah chapter of the American Academy of Pediatrics, told MedPage Today.

The level of community spread is such that big super-spreading events like the recent state wrestling championship “keep popping up,” Brownstein added.

They’re kindled by the state’s comparably lower immunization rates; about 10% of children entering kindergarten have measles, mumps, and rubella (MMR) vaccine exemptions, she said.

In addition, early symptoms “look like the common cold … and people may not realize what they have until a rash shows up 4 days later. This makes it easier for it to be spread to others,” a spokesperson for Utah’s DHHS told MedPage Today.

The spokesperson confirmed that “fewer than 11 clinicians” have been infected with measles in the state. In a health alert issued earlier this month, DHHS noted that a number of clinicians with breakthrough infections had “continued to provide care while symptomatic, not realizing they had measles.”

It’s not surprising that some clinicians would develop breakthrough infections given that measles is one of the most contagious diseases in the world, the spokesperson said.

“While the measles vaccine is very good at protecting people, it is not perfect,” DHHS stated. “Most people who get the vaccine (97%) are well protected, but about 3% can get sick if they are exposed to the measles virus. During an outbreak, breakthrough infections are expected because high levels of the measles virus are circulating in the community.”

Even if a vaccinated individual gets measles, “there are still benefits from the vaccine,” such as being less likely to have severe illness or complications, or to spread the virus to other people, the agency noted.

DHHS urged clinicians to have “heightened awareness of measles-like symptoms” even if they have been vaccinated.

The agency also advised physicians to discuss the option of giving infants ages 6- to 12- months an early, extra dose of the MMR vaccine amid the ongoing outbreak. It also noted that it’s appropriate to give a second dose of the MMR vaccine to people born before 1989 who may have received just 1 dose.

Brownstein noted the importance of one-on-one conversations with families who may be vaccine-hesitant. And it may be individual stories about the seriousness of measles or hospitalizations from measles that move people who are “on the fence” about vaccination, she said.

“It suddenly takes it [from], ‘they’ll do fine with measles’ to, ‘oh, maybe they don’t,'” Brownstein said.