Pennsylvania health officials said a fourth person had died of measles-associated illness in the worst year for the disease since 1992. All four US deaths have occurred in the state.
Due to the Trump administration changing how it reports measles deaths, the Centers for Disease Control and Prevention (CDC) does not count any of the deaths in its national tally. Three people died in 2025.
“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,” Dr Debra Bogen, Pennsylvania’s secretary of health, said in a statement. Pennsylvania has reported nearly 700 cases of measles.
“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 [measles, mumps and rubella] vaccine – which kept measles outbreaks at bay for decades,” she said.
One to three people per 1,000 die of measles-related complications, such as pneumonia and neurologic complications. The measles-associated death announced Tuesday was of an 18-year-old Mifflin county resident, who was diagnosed with encephalomyelitis, a rare and severe neurological complication of the virus. Up to one in five people infected with the disease will be hospitalized.
Pennsylvania’s agricultural areas in Lancaster and Mifflin counties have been the center of the state’s outbreak. Utah, Florida, Virginia and Texas have also seen dozens of cases, according to tracking from Johns Hopkins University.
The US has seen more than 3,300 cases in 2026. Epidemiological data is generally considered an undercount. Measles is one of the most contagious diseases known to medicine. The measles, mumps and rubella vaccine, or MMR, prevents 97% of measles cases. However, vaccination rates among kindergarten-aged children, considered a bellwether, have experienced a slow decline as experts argue the administration spreads confusion among parents.
Robert F Kennedy Jr, the US health secretary and head of an anti-vaccine advocacy group before he took office, has upended federal vaccine policy and made multiple misleading statements about the MMR vaccine since taking office.
The US eliminated measles in 2000, though it is unclear whether it can retain that status amid recent outbreaks. Globally, measles remains the leading cause of vaccine-preventable infant death.
