U.S. Measles Cases Reach Three-Decade High
The United States has recorded 2,318 measles cases so far in 2026, surpassing the 2,289 cases reported during all of 2025, according to the Centers for Disease Control and Prevention. With five months remaining in the year, 2026 is now the country’s worst year for measles since 1991.
Major outbreaks in South Carolina, Utah and Arizona have accounted for hundreds of infections, while smaller clusters have emerged elsewhere. South Carolina has reported 997 cases, although state officials say the total is probably incomplete. More than 700 people have become ill during an outbreak affecting Utah, and researchers estimate that transmission near the Utah-Arizona border could be three to four times larger than official figures indicate.
Public health experts say case totals often understate the spread because some infected people do not seek medical care. Inconsistent hospitalization reporting and uneven surveillance also make it difficult to assess the full scale of outbreaks.
Vaccination coverage is a central concern. The national measles, mumps and rubella vaccination rate among kindergartners fell from 95.2 per cent in 2019-20 to 92.5 per cent in 2024-25. Health officials generally identify 95 per cent coverage as the level needed to limit outbreaks. Rates are lower in some communities.
Canada has reported 1,102 cases in 2026, most involving children, after recording 5,462 cases in 2025 and losing its measles elimination status.
International health officials are expected to review in November whether the United States and Mexico have also lost measles-free status. Researchers emphasize that outbreaks pose particular risks to infants, immunocompromised people and others who cannot be vaccinated or do not develop strong immunity.
They say maintaining accurate surveillance and improving vaccination coverage will be important for tracking transmission, limiting further spread and protecting people who face the highest medical risks overall.