Measles multistate outbreak reaches 35-year high
Key Questions
How many measles cases have been reported in the US in 2026?
The US has logged 2,318 confirmed cases, surpassing last year's total and reaching a 35-year high. Models suggest actual numbers could be 3-4 times higher due to undercounts across 35+ states.
What percentage of measles cases involve unvaccinated individuals?
93% of cases are unvaccinated. Kindergarten MMR rates below 95% in multiple areas and rising religious exemptions are driving transmission.
Which states have declared measles outbreaks recently?
Delaware declared an outbreak after four unvaccinated adult cases in Kent County. Pennsylvania has 61 cases, and new clusters appeared in Ohio's Ashtabula County and elsewhere.
How is misinformation affecting the measles outbreak?
Political misinformation has fueled declining vaccination rates and a surge in cases. Analyses link anti-vaccine messaging directly to the resurgence of a previously eliminated disease.
What actions are health departments taking in response to outbreaks?
Officials urge MMR catch-up for adults and infants 6+ months, release exposure locations, and promote immunity testing. Delaware issued practical Q&A guides for residents.
Are there breakthrough measles infections in vaccinated people?
A vaccinated adult in East Idaho contracted measles near the Wyoming outbreak area. This highlights risks when community coverage falls below herd immunity thresholds.
What travel-related measles risks are being highlighted?
Cases linked to Grand Teton National Park and international travel underscore summer risks. Health officials recommend checking MMR status before trips.
How do doctors describe the clinical impact of current measles cases?
Front-line physicians report severe symptoms like tripoding and barking cough, plus parental regret. They emphasize the human cost and need for proactive adult vaccination.
A September 25 federal update reports at least 3,659 confirmed U.S. measles cases in 2026, 40 outbreaks, and 95% of cases associated with outbreaks across more than 35 states. Congressional scrutiny is also focused on measles reporting; adults with one or unknown MMR doses and international travelers should verify protection, while the routine MMR schedule remains unchanged.