A teenager in Pennsylvania has died following measles complications, becoming the fourth person in the state to die from the highly contagious virus this year.
Andrea Alcalde, the coroner for Mifflin County — located roughly 150 miles from Pittsburgh — confirmed Tuesday that the unvaccinated 18-year-old died from complications linked to measles.
The teen, whose identity has not been made public, died from acute disseminated encephalomyelitis, according to the coroner. The rare but serious neurological disorder can be associated with measles and triggers inflammation in the brain.
Officials did not release additional information about the teenager.
The death was reported only days after public health authorities said an unvaccinated 40-year-old woman in neighboring Jefferson County died over the weekend from “complications associated with measles.”
Pennsylvania has now reported four measles-related fatalities in 2026, its first deaths connected to the virus in 35 years.
The state’s other two deaths involved infants in Lancaster County.
As of September 14, Pennsylvania’s measles outbreak had reached 693 confirmed cases, including 99 reported over the previous week. A total of 133 people have required hospitalization, while fewer than one percent of patients had received both recommended doses of the measles, mumps and rubella, or MMR, vaccine.
An 18-year-old Pennsylvania woman died Saturday due to measles-related complications (stock image)
The Pennsylvania Department of Health stressed that becoming fully vaccinated remains the strongest protection against measles.
The MMR vaccine, which is given once between ages 12 and 15 months and again between ages four and six, is thought to be 97 percent effective in preventing measles, according to the Centers for Disease Control and Prevention (CDC).
For unvaccinated people, nine in ten of those exposed to the virus will get infected.
‘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,’ Pennsylvania Secretary of Health Dr Debra Bogen said Tuesday.
‘We remain committed to working with our partners across Pennsylvania to stem this outbreak and prevent more deaths. That means ensuring people have the facts about measles and access to the MMR vaccine – which kept measles outbreaks at bay for decades.’
The first two measles-related deaths in Pennsylvania were newborn baby Ivan S Miller from Strasburg Township in Lancaster County, and six-week-old Mary S Stoltzfus from Fulton Township.
Neither was old enough to be vaccinated.
CDC data updated September 11 shows 3,294 measles cases nationwide so far this year, well surpassing last year’s total of 2,289. About 95 percent of infections this year have been in unvaccinated individuals.
Measles, which is highly infectious, is characterized by cough, fever, a distinctive blotchy rash that starts on the face before spreading down the body and tiny white spots inside the mouth called Koplik spots.
The virus spreads through direct contact with infectious droplets or through the air. Patients with a measles infection are contagious from four days before the rash through four days after the rash appears. Enclosed areas like airports and planes are extremely risky locations for disease transmission.
It first invades the respiratory system, then spreads to the lymph nodes and throughout the body. As a result, the virus can affect the lungs, brain and central nervous system.
MMR vaccines (center) sit inside a medical refrigerator. The shot is typically given once between ages 12 and 15 months and again between ages four and six
The above CDC map updated September 11 shows measles cases by state for 2026
While measles sometimes causes milder symptoms, including diarrhea, sore throat and achiness, it leads to pneumonia in roughly six percent of otherwise healthy children, and more often in malnourished children.
Though the brain swelling that measles can trigger is rare, occurring in about one in 1,000 cases, it is deadly in roughly 15 to 20 percent of those who develop it, while about 20 percent are left with permanent neurological damage, such as brain damage, deafness or intellectual disability.
Measles also severely damages a child’s immune system, making them susceptible to other potentially devastating bacterial and viral infections they were previously protected against.
Before MMR vaccines became available in the 1960s, measles caused epidemics with up to 2.6 million global deaths every year. By 2023, that number had fallen to roughly 107,000 deaths.
Nationwide, 92.4 percent of kindergarteners are fully vaccinated against measles, below the CDC’s 95 percent threshold for herd immunity. In Pennsylvania, the MMR vaccination rate is 94.6, while rates in Maryland and Iowa are 96 and 90 percent, respectively.
Exemptions are also on the rise at 4.2 percent, up 17 percent from 1.6 percent just over a decade ago.