US Measles Cases Double Last Year's Total, Surpassing 4,500

The US Centers for Disease Control and Prevention (CDC) confirmed 4,588 measles cases, representing a weekly rise of 178 cases and more than double last year's national total. Over the past two weeks alone, 508 new infections were confirmed — surpassing the entire combined national total of 465 cases recorded from 2022 through 2024. There are currently 43 active outbreaks across the country, where an outbreak is defined as three or more linked cases. Pennsylvania remains the epicentre, accounting for nearly 30% of all cases with 1,338 infections across 44 counties, five confirmed deaths, and a sixth under investigation. Nationwide, the CDC acknowledges three measles deaths. Ten percent of all confirmed cases required hospitalisation, climbing to 16% among children under five; 17% of all cases have been in children under five, and 42% in those aged five to 19. Ninety-six percent of patients were unvaccinated or had unknown vaccination status. An infectious disease expert presenting at IDWeek estimated the true US case count since the start of last year could exceed 20,000 due to widespread underreporting. Since the beginning of 2025, 6,877 confirmed cases have been tallied — a toll that puts the nation at risk of losing the measles elimination status it achieved in 2000. Pennsylvania has responded by administering more than 6,500 MMR doses at pop-up clinics since the outbreak began in late April.