Eighteen-Year-Old Dies from Measles Complications in Pennsylvania

<p>The Pennsylvania Department of Health confirmed on September 15, 2026, that a fourth person has died from measles in the state. The deceased was an unvaccinated 18-year-old resident of Mifflin County.</p><p>The state health department also reported the recent death of an unvaccinated 40-year-old woman in Jefferson County, as confirmed by a county coroner's report. Previously, two deaths had been reported in Lancaster County, both involving infants—a newborn boy and a 6-week-old girl—who were too young to be vaccinated.</p><p>According to Mifflin County coroner Andrea L. Alcalde, the cause of death for the 18-year-old was acute disseminated encephalomyelitis (ADEM), a rare but known severe complication associated with measles. ADEM is characterized by a rapidly progressing autoimmune disorder that results from inflammation caused by an infection, which damages the protective coverings of nerve cells in the brain and spinal cord. Historically, ADEM was commonly linked to measles prior to the widespread use of measles vaccines, although other viral infections can also trigger its onset.</p>