Pennsylvania health officials have confirmed a fourth death connected to measles.
The latest death involved an 18-year-old resident from Mifflin County, in the state’s central region, the local coroner’s office stated in a Facebook post.
The cause was acute disseminated encephalomyelitis, a rare and severe neurological complication resulting from measles.
On Saturday, a 40-year-old woman from western Pennsylvania’s rural Jefferson County died of measles complications. Meanwhile, two infected infants passed away last month in southeastern Pennsylvania’s Lancaster County.
None of the four individuals were vaccinated, according to the state health department. Current medical guidelines state the infants were too young for vaccination.
The U.S. is undergoing its worst year for measles since 1991, with seven reported measles-associated fatalities over the past two years — higher than the combined total of reported deaths across the preceding three decades.
Pennsylvania’s outbreak is expanding, with nearly 700 cases reported this year across 38 counties, including roughly 100 within the past week. State officials said these are the first measles-related deaths in the state in 35 years.
“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,” the state’s health secretary, Dr. Debra Bogen, said in a statement Tuesday, referring to the two recent adult fatalities.
“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.”
Domestic spread of measles was eliminated in the U.S. in 2000 by maintaining high vaccination coverage, but rates have recently dropped beneath the 95% threshold needed to prevent outbreaks, causing infections to surge.
In November, international health authorities will gather to decide whether the U.S. and Mexico have lost their measles-free status.
The problem has mounted over several years as fewer children receive routine immunizations due to parental exemptions, healthcare access obstacles, and widespread disinformation.
More recently, Trump administration health officials, including Health Secretary Robert F. Kennedy Jr., have questioned vaccine safety at an unprecedented level while defunding local initiatives aimed at improving vaccination rates.
