The Pennsylvania Department of Health confirmed a fourth measles-associated death Sept. 15, an unvaccinated 18-year-old who lived in Mifflin County.
The Mifflin County coroner’s office said the cause of death was acute disseminated encephalomyelitis, a rare and severe neurological complication of measles. State officials did not release additional details about the individual, citing privacy laws.
The same announcement formally confirmed the state’s third measles-associated death, a 40-year-old woman in Jefferson County, Pa., whose death the county coroner disclosed Sept. 12. Both new deaths will appear on the state’s measles dashboard Sept. 16.
“My thoughts are with the two families who lost loved ones to this highly contagious virus, as Pennsylvania faces the worst measles outbreak in more than three decades,” Secretary of Health Debra Bogen, MD, said in a Sept. 15 news release. “We remain committed to working with our partners across Pennsylvania to stem this outbreak and prevent more deaths.”
Pennsylvania has confirmed 693 measles cases across 38 counties in 2026. Its first two measles-associated deaths, reported Aug. 25 in Lancaster County, Pa., were the state’s first in 35 years. The CDC has excluded those two from its national count pending review, leaving the federal dashboard listing zero U.S. measles deaths for 2026.
The Mifflin County death moves the outbreak further from its Lancaster County epicenter and marks the second fatality in an adult or older teenager. Roughly 20% of people identified with measles are hospitalized in Pennsylvania, and historical data puts measles-associated deaths at 1 to 3 per 1,000 cases.
