So far this year, 57 Utah residents have been diagnosed with measles. By comparison, a total of 285 measles cases were reported across the entire United States in 2024.
Dr. Leisha Nolen, Utah’s state epidemiologist, said Utah’s cases this year have been a mix of out-of-state exposures and ongoing outbreaks.
“Our first introduction of measles into the state was in Utah County," Nolen said, "and that was an individual who clearly had traveled, and we could tell that they got it somewhere else. Happily, they didn't really spread it to many other people. Unfortunately, we did then have an exposure down next to the Utah-Arizona border, and that outbreak has been continuing.”
Of the 57 Utah measles cases this year, 43 have been residents of the Southwest Utah health district. Nolen said this is the largest outbreak the state has seen in decades.
“I think the first thing for people to know about measles in Utah is, while we are having cases, the vast majority of Utahns are not at risk,” Nolen said.
The MMR vaccine, required for kindergarten entry across all 50 states, is 97% effective against measles infection.
“Most adults have gotten this vaccine. It's a vaccine that's been proven to be safe for a long time,” Nolen said.
People of all ages who have not previously contracted or been vaccinated against the measles are extremely likely to contract the disease if exposed.
“Measles is the most infectious disease we know of," Nolen said. "You put somebody in a room, a classroom with measles, and if those other people in that room don't have the vaccine, they are going to get sick with it. Measles can hang in the air for hours.”
While measles symptoms can sometimes be mild and clear up without treatment, they vary from person to person. Usually, symptoms develop about a week after exposure to the virus.
“And the first things they start to get are pretty generic symptoms. They look like any other cold, unfortunately," Nolen said. "But after four or five days, they then develop this rash, and that's when people usually start to realize something else is going on,” Nolen said.
In extremely severe cases, Nolen said, people can develop infections of the brain.
“And that can cause them to have really long-term problems with thinking, with movement," Nolen said. "Happily, that's not exceptionally common, but it does occur. And we know if we have enough people get measles here in Utah, the chances are, one of them will have that kind of really severe infection."
The Utah Department of Health and Human Services “2025 measles response” webpage is updated daily with known exposure locations and dates.
To prevent the spread of measles, try to minimize contact with other people if you suspect you might be infected.
“We encourage people, if they have any of those symptoms and have any reason to think they have measles, that they call ahead to wherever they're going," Nolen said. "So if it's their doctor's office, if it's the emergency room, call ahead. That way, they can make sure that you come in from maybe an alternate site, so you don't expose so many people, or that they can get you through the waiting room really fast, so that you also don't cause people to sit there next to you and get measles.”
