The measles outbreak along the Utah-Arizona border continues to grow and is now at 158 cases, according to updates from the two states’ health departments.
In Utah, the Southwest Utah Health Department has reported two new measles cases, bringing its total for the year to 51 cases. Most of the cases are in Hildale in Washington County, but the two new cases were reported in St. George, also in Washington County, and in Cedar City in Iron Horse County.
Utah has now reported 67 measles cases overall for the year, with 9 hospitalizations, according to an update yesterday from the Utah Department of Health and Human Services. The cases are evenly split between children under 18 (34 cases) and adults (33). Of the 67 measles patients, 65 are unvaccinated.
The outbreak in Washington County has prompted state health officials to recommend that infants aged 6 months to 1 year who live in or are traveling to the county get a dose of the measle, mumps, and rubella (MMR) vaccine, the Salt Lake Tribune reported last week. Typically, the first MMR shot is administered at 12 to 15 months.
Of the 111 measles cases that have been confirmed to date in Arizona, 107 are in Mojave County, which borders Washington County, and 4 are in neighboring Navajo County, the outbreak update from the Arizona Department of Health Services shows. The case count has risen by 14 since the last update. The state reported its first measles cases in June.
The Utah-Arizona measles outbreak is the second largest in the country, after the West Texas outbreak, which sickened at least 762 people, with 3 deaths.
National total rises by 33 cases
Nationwide, the number of measles cases has risen by 33 over the past week, the Centers for Disease Control and Prevention (CDC) reported today in its latest update. The total for the year is now 1,681 confirmed cases—the highest number of cases in the country since measles was declared eliminated in 2000. Only 285 US measles cases were reported last year.
The outbreaks in Utah and Arizona are among the 44 reported in 2025. Of the confirmed cases, 87% are outbreak-associated. Outbreaks are defined as three or more related cases.
Ninety-two percent of the US measles case-patients this year are unvaccinated or have unknown vaccination status. Twelve percent of case-patients have been hospitalized, with more than 1 in 5 hospitalizations (22%) occurring in children under 5.
Two shots of the MMR vaccine are 97% effective against measles. But recent data from the CDC show MMR uptake among US kindergartners fell to 92.5% in the 2024-25 school year, down from 95.2% in the 2019-20 school year, and several communities around the country have MMR vaccination rates below 90%. Maintaining measles elimination status requires a minimum of 95% vaccination coverage.
