The Centers for Disease Control and Prevention listed one confirmed measles death nationally for 2026 on its data page updated Sept. 23, even as Pennsylvania health officials counted four measles-associated deaths within that state alone, exposing a dispute over how outbreak deaths get certified.
Measles Cases Climb Far Above 2025 Levels
The CDC’s measles data page, current through Sept. 17, listed 3,471 confirmed cases nationally for 2026. The agency separately reported 3,063 indigenous cases through the week ending Sept. 12 in its National Notifiable Diseases Surveillance System, according to Global Biodefense. The two figures differ because they reflect different reporting dates, not a correction of one by the other.
Both counts run far above 2025, when the country recorded 2,289 measles cases for the full year. The Sept. 12 comparison point showed 1,374 cases in the same period of 2025, a 123% increase year over year, Global Biodefense reported, citing CDC surveillance data.
South Carolina drove much of the increase, climbing to 686 cases in 2026 from a single case in 2025. Pennsylvania rose to 649 cases from 12, and Utah rose to 531 cases from 27, according to the same CDC-sourced figures. Measles was declared eliminated in the United States in 2000, meaning the virus no longer spread continuously within the country. The 2026 totals mark one of the largest resurgences since that declaration.
The rise has coincided with a decline in childhood vaccination. The measles, mumps and rubella vaccination rate among kindergartners fell to 92.4% this year from 95% a decade ago, according to CDC data cited by Scientific American.
Pennsylvania Counts Four Deaths, CDC Recognizes One
Pennsylvania’s health department has recorded 731 measles cases across 38 counties and 141 hospitalizations this year, according to state data cited by Medical Daily. Four of those cases ended in death, by the state’s own classification.
State officials confirmed two deaths in Lancaster County in August, both in unvaccinated people, marking Pennsylvania’s first measles fatalities in 35 years. Two more deaths followed in September, one in Jefferson County and one in Mifflin County. The Mifflin County patient, 18, died of acute disseminated encephalomyelitis, a rare neurological complication that can follow a measles infection.
Pennsylvania Secretary of Health Debra Bogen said the state’s long absence of measles left residents unprepared for what the disease can do. “Because measles was largely eliminated in the Commonwealth for more than three decades, people are not familiar with this disease and don’t fully understand the potential severity of the illness,” Bogen said, according to Scientific American.
The CDC’s national count does not reflect Pennsylvania’s tally. HHS spokesperson Emily Hilliard said the CDC will not add a death to its official count until a separate federal system confirms it. “The CDC will report measles deaths if and when the National Center for Health Statistics reports measles as the underlying cause of death,” Hilliard said, according to Medical Daily.
Pennsylvania classifies a death as measles-associated when laboratory testing or epidemiologic evidence shows measles was present, even without a death certificate formally naming it as the underlying cause. That standard is faster and broader than the NCHS process the CDC relies on, which requires a certified death certificate before a case enters the national count.
The CDC has not said whether it disputes any of Pennsylvania’s four cases individually, only that its own tally depends on the NCHS certification step.
Shapiro and Kennedy Clash Over Measles Data
The gap between the two counts has become a point of conflict between Pennsylvania’s governor and the federal health department. Pennsylvania Gov. Josh Shapiro accused Health and Human Services Secretary Robert F. Kennedy Jr. of spreading “misinformation that’s led to real-life consequences,” according to PhillyVoice.
Kennedy has faced criticism from public health officials over his handling of vaccine policy and messaging during the outbreak. The CDC’s insistence on the NCHS standard, even as state officials report additional deaths, has become part of that broader dispute over how the federal government communicates the outbreak’s severity to the public.
Why a Death-Certificate System Misses Outbreak Deaths
The disagreement traces to a mismatch between what the NCHS system was designed to do and what it is now being used for. Debra Houry, former CDC chief medical officer, has said the certification process is built for long-term mortality trend analysis rather than confirming an individual case during an outbreak, according to Medical Daily.
That distinction has concrete consequences
Lancaster County Coroner Stephen Diamantoni said his office keeps no formal “measles deaths” category in its records. But Diamantoni confirmed examining a case involving a newborn who had tested positive for measles. The infant’s official cause of death was listed as a ruptured spleen, with no mention of measles on the certificate, according to PhillyVoice.
Under the NCHS standard the CDC uses, that case cannot become part of the national measles death count, regardless of what role the infection played, because the certifying document names a different immediate cause. The system was built to aggregate death records over years to identify long-range patterns in what Americans die from, not to adjudicate in real time whether a specific infection caused a specific death during an active outbreak.
A coroner or physician filling out a death certificate typically records the immediate physical cause, such as organ failure or a ruptured spleen, and may not list the underlying infection that triggered it, particularly when that connection takes time to establish.
The result is a structural gap: deaths tied to measles can move through the medical examiner system, appear in local case records and prompt state-level classification as measles-associated, yet never surface in the CDC’s official tally because no death certificate specifically names measles as the underlying cause. Pennsylvania’s four counted deaths already sit outside the CDC’s total for exactly that reason.
The Lancaster County newborn shows the gap can extend even further, since that case has not surfaced in either agency’s public count under a measles designation.
What Happens Next
The CDC has said on its own data page that it continues reviewing additional cases and will update its national count as more information becomes available. The agency has not said whether it will add Pennsylvania’s remaining deaths to its national tally, or on what timeline the NCHS certification process might resolve those cases. Pennsylvania’s health department has not indicated it will revise its own count downward to match the CDC’s standard.
With case totals still climbing nationally and vaccination rates continuing to slide below the threshold needed for herd immunity, officials in both the state and federal systems face pressure to reconcile how they report an outbreak that neither number, on its own, fully captures.
