The Centers for Disease Control and Prevention confirmed 5,182 measles cases across 45 states and Washington, D.C., as of November 5, 2026, marking the highest annual U.S. total since the country logged 9,643 cases in 1991.
How Measles Surpassed 1990s Totals
The confirmed case count more than doubles the 2,289 infections recorded across the entirety of 2025. Federal data shows that 96 percent of confirmed infections are outbreak-associated, stemming from 43 separate outbreaks tracked this year.
Children and teenagers account for roughly 59 percent of all confirmed cases. Children under five represent 18 percent of the total, while patients between five and 19 make up 41 percent.
Nationwide, 562 patients have required hospitalization, representing roughly 11 percent of all reported infections.
Measles Vaccine Coverage Drops Among Kindergartners
The rapid transmission coincides with a drop in measles, mumps, and rubella vaccine coverage among U.S. kindergartners. Immunization coverage fell from 95.2 percent during the 2019–2020 school year to 92.4 percent in the 2025–2026 school year.
Epidemiologists view the 95 percent threshold as essential for population-level protection.
According to federal health data, about 96 percent of 2026 infections occurred in individuals who were unvaccinated or whose vaccination status was unknown.
Just 2 percent of cases occurred in people who received a single MMR dose, and another 2 percent in those who received the recommended two doses.
State Health Departments Report Higher Fatalities than Federal Tallies
Federal and state tallies over measles-related fatalities have diverged significantly during the outbreak. While the CDC officially lists four deaths tied to the virus, state health departments have reported at least eight fatalities across Pennsylvania, New York, and Wisconsin.
Pennsylvania’s Department of Health reported six deaths and 1,487 cases, making it the hardest-hit state in the country.
New York state health officials reported a child’s death in the rural northern part of the state — the first measles-associated death in the state in more than three decades.
Wisconsin health officials confirmed an infant death on November 5, marking the state’s first measles fatality since 1990.
The federal government’s official count has sat at the center of a public dispute between Pennsylvania Governor Josh Shapiro and U.S. Health and Human Services Secretary Robert F. Kennedy Jr. concerning the specific criteria used to classify measles deaths.
Pennsylvania registers measles-associated deaths when any individual with confirmed measles dies within 30 days of developing symptoms, provided the death was not caused by an unrelated event.
Following directives from the HHS Secretary to question whether the virus directly caused or contributed to the fatalities, the CDC temporarily removed two Pennsylvania deaths from its national tally.
Infectious disease experts note that tracking measles-associated deaths in this manner aligns with longstanding standards upheld by the World Health Organization and the CDC. Experts warn that departing from these definitions creates discrepancies with state-level tracking.
Across the country, health departments in New York, Pennsylvania, and Wisconsin logged three additional measles-associated deaths during a single week in early November.
None of those three jurisdictions had recorded a measles-related fatality in over thirty years prior to the current resurgence.
The Wisconsin Department of Health Services reported that an infant passed away with measles, marking the first such fatality in the state since 1990.
Simultaneously, the New York State Department of Health confirmed a fatality in an upstate child, representing the state’s first measles-associated death in more than thirty years.
In response to the accelerating caseload, New York Governor Kathy Hochul declared a state disaster emergency in October.
Geographic spread has extended across 45 states and the District of Columbia. Aside from Pennsylvania’s leading figures, states like South Carolina and Utah have documented substantial disease burdens, logging 670 and 536 confirmed cases respectively.
Meanwhile, international visitors accounted for 18 of the total confirmed cases nationwide.
An expert commission convened by the Pan American Health Organization evaluates whether the United States preserves its official measles-eliminated classification, a designation maintained since 2000.
The burden of these diseases will fall on children, who are not the ones who are making these decisions.
Pediatrician Adam Ratner
Outpatient Offices Miss Measles Cases Before Accurate Diagnoses
A study published in Infection Control and Hospital Epidemiology found that an estimated 6.9 percent of patients who sought care were misdiagnosed at least once before receiving an accurate diagnosis.
Outpatient doctor’s offices accounted for 81 percent of missed cases, while emergency departments accounted for 14 percent.
Researchers noted that diagnostic delays averaged just over four days.
Misdiagnoses occurred more frequently among very young children and patients who received respiratory antibiotic prescriptions.
For measles, it spreads through airborne means, which means that once [an infected person breathes] it out, it actually stays circulating in the air for up to two hours after they leave that room.
Dr. Andrew Handel
Earlier coverage: Pennsylvania measles outbreak hits 1,400 cases as parents weigh MMR effectiveness
