Utah Measles Outbreak Now Most Active in U.S.

Utah Becomes Epicenter of U.S. Measles Outbreaks as South Carolina Cases Decline

Utah has officially grow the epicenter of measles outbreaks in the United States. While South Carolina previously held the largest outbreak in recent history, a significant drop in new cases there has shifted the focus to Utah, where the virus remains highly active.

According to the Center for Infectious Disease Research and Policy (CIDRAP), Utah now leads the nation in active measles transmission. Health officials have recorded 583 confirmed cases in the state since the outbreak began last year, with a sharp increase in activity occurring throughout early 2026.

Utah’s Current Outbreak Status

The surge in Utah is marked by a rapid increase in recent diagnoses. Of the 583 total cases, 386 were recorded in 2026 alone. The situation has intensified in the last few weeks, with 121 cases reported in the previous three weeks and 24 new cases appearing in the past week.

The outbreak has heavily impacted specific regions within the state. The most significant hotspots include:

• Southwest Health Area: 249 cases (covering Washington, Iron, Kane, Beaver and Garfield counties).
• Utah County: 93 cases.
• Salt Lake County: 62 cases.
• TriCounty Health Department Area: 59 cases (covering Daggett, Duchesne, and Uintah counties).
• Central Utah Public Health Department Area: 50 cases (covering Juab, Millard, Piute, Sanpete, Sevier, and Wayne counties).

The clinical impact has been severe, with 47 people requiring hospitalization. Demographically, the virus has primarily affected younger populations. 383 of the confirmed cases are individuals under the age of 18, while 200 are adults.

South Carolina’s Outbreak Nears Official Conclude

While Utah struggles with rising numbers, South Carolina is moving toward the official conclusion of its outbreak. Since it began on October 2, 2025, South Carolina has seen 997 cases, making it the largest U.S. Measles outbreak in recent history. The virus originally seeded in several private elementary and middle schools where vaccination rates were low.

The state has not reported a new case since March 17. Public health officials require a period of 42 days—double the standard 21-day incubation period—with no new cases to declare an official end to an outbreak. If this trend continues, the South Carolina outbreak will officially end on April 26.

Data regarding the 997 infected individuals highlights a strong correlation between vaccination status and infection:

• Unvaccinated: 932 cases
• Partially vaccinated: 20 cases
• Fully vaccinated: 26 cases
• Unknown status: 19 cases

Age-wise, 639 cases occurred in those aged 5 to 17, and 264 were in children under the age of 6.

Other Regional Activity

Measles activity has also been noted in the Pacific Northwest. Washington State has recorded 33 cases so far this year. In Snohomish County, officials recently announced the end of an outbreak that ran from January 15 to February 17, resulting in 14 total cases.

Key Takeaways: U.S. Measles Trends 2026

Public health officials continue to monitor these outbreaks closely. The transition of the “epicenter” from South Carolina to Utah underscores the ongoing challenge of maintaining high vaccination rates to prevent the breakdown of transmission chains in community settings.