US measles cases climb above 5,000 for first time since 1991

In 2026, the United States saw a spike in measles cases, surpassing the 5,000 mark for the first time since 1991, according to the Centers for Disease Control and Prevention. The majority of these infections occurred among unvaccinated individuals or those with unknown vaccination status, making up 96% of the reported cases. Pennsylvania bore the brunt of the outbreak, with 1,487 cases and 287 hospitalizations, while Wisconsin reported an infant's death and New York its first measles-associated death in over three decades.

South Carolina and Utah followed with 670 and 536 cases, respectively. The nation recorded four measles-associated deaths in 2026, a discrepancy from the CDC's four reported deaths in 2025, which was due to a change in data tracking methods. The hospitalization rate stood at 11%, with the majority of cases (2,132) in people aged 20 and older, followed by 2,104 among those aged 5-19 and 908 in children under 5.

There were 43 new outbreaks reported this year. The Pan American Health Organization is set to decide if the U.S. still meets measles elimination criteria, a status it has maintained since 2000.