Utah measles outbreak declines to six cases in three weeks

The Utah Department of Health and Human Services said that only six new measles cases were reported in the last three weeks, a sharp decline from the outbreak’s peak of 58 cases in a single week in March. The outbreak, which began in June 2025, has affected 707 people, most of whom were school-aged children, and resulted in 56 hospitalizations but no deaths.

State epidemiologist Leisha Nolen noted that the reduction reflects higher vaccination rates, natural immunity development, and the summer break, which limits school-based transmission. She added that while the situation has improved, the goal remains zero cases and that continued vaccination is essential, especially before schools reopen.

Health officials emphasized that the two-dose MMR vaccine is about 97% effective and urged residents to get vaccinated promptly. They reported that 27,000 more Utahns received the vaccine this year compared with the previous year, though coverage is still incomplete.

Wastewater testing suggests some infections may remain undetected, but overall trends indicate reduced spread. Hospitalizations have primarily been for dehydration, respiratory difficulties, and, in a few instances, complications such as appendicitis or liver inflammation.

Nolen warned that measles can weaken immune memory, potentially leading to more severe illness from other infections, and mentioned the rare risk of a delayed brain inflammation that can be fatal. The department currently has no designated exposure sites and advises the public to monitor for symptoms.