Measles Outbreak Spreads Beyond Utah-Arizona Border, 123 Cases Reported

THURSDAY, Oct. 23, 2025 (HealthDay News) — A growing measles outbreak along the Utah-Arizona border has spread to nearby communities, making it the nation’s second-largest this year, health officials confirmed.

At least 123 people have been infected, most linked to two small towns — Colorado City, Arizona, and Hildale, Utah — where residents often move between the two communities. 

Within recent weeks, cases have also appeared in nearby Utah cities of Hurricane and St. George, after exposures in hospitals and urgent care clinics, according to the Southwest Utah Public Health Department.

Many of the clusters started in schools, department spokesperson David Heaton told NBC News. "But now we have community spread," he added.

The outbreak has also reached Iron County, Utah, just north of the original epicenter.

Health officials have long warned that this region is vulnerable to measles because of low childhood vaccination rates. 

According to NBC News data:

• In Iron County, 82.4% of children are vaccinated against measles.

• In Washington County, that rate drops to 79.2%, and in Mohave County, Arizona, it’s 78.4%, far below the 95% threshold needed for herd immunity.

“We were preparing for it,” Heaton said. “It was a matter of time before it came here.”

Most cases so far have occurred among unvaccinated school-aged children, officials said. Utah has reported six measles-related hospitalizations, five of which are tied to the current outbreak zone.

The area includes popular tourist destinations like Zion National Park, raising concerns about possible exposure to visitors.

The outbreak mirrors a broader national decline in childhood vaccination. According to NBC News data, 77% of U.S. counties and jurisdictions have seen drops in vaccination rates.

During the 2024–2025 school year, 4.1% of kindergartners (about 138,000 children) had exemptions from required vaccines, surpassing last year’s record of 3.7%. Nearly all exemptions were for non-medical reasons, such as religious or personal beliefs.

Despite the ongoing federal government shutdown, the U.S. Centers for Disease Control and Prevention (CDC) has continued to track measles cases. As of Oct. 21, the CDC reported 1,618 infections across 42 states.

More information

The U.S. Centers for Disease Control and Prevention has more on measles.

SOURCE: NBC News, Oct. 22, 2025

What This Means For You

This current outbreak is further proof that measles spreads quickly when people aren’t protected.