A Pennsylvania measles outbreak has spread to Philadelphia International Airport, where at least two cases of the highly infectious disease have been traced to the airport’s terminals B and F.
Travelers passing through these two terminals, as well as areas connecting to terminals C, D, and E, between Sunday, Sept. 13, from 7:45 p.m. and Monday, Sept. 14, at 12:05 a.m., may have been exposed to active measles carriers, according to the Philadelphia Department of Public Health.
People who were in these areas and may have been exposed to measles have been advised to quarantine until Oct. 5.
The exposure was traced to an airline passenger who was transiting the airport and did not leave the building. However, a measles outbreak and exposure have also affected patients, staff, and visitors at the Children’s Hospital of Philadelphia.
Measles Makes a Comeback
The state of Pennsylvania has reported 792 cases of measles in 2026, including 155 cases requiring hospitalization and two measles-related deaths. A total of 97 new cases were reported in the week leading up to Sept. 21, the date of the last statewide report compiled by the Pennsylvania Department of Health.
Nearly all of the cases have been among people who have not been vaccinated against the disease: less than one percent of measles infections reported occurred among vaccinated individuals.
The two measles deaths were the first reported in the state in 35 years. Measles was declared eliminated in the U.S. in 2000. However, there have been a series of measles outbreaks since 2025, and the U.S. Centers for Disease Control and Prevention has reported 3,471 measles cases nationally year to date.
Infectious disease experts point to a decline in vaccination rates and vaccine skepticism that has peaked since Robert F. Kennedy Jr. became head of the U.S. Department of Health and Human Services under the Trump administration. Kennedy reaffirmed his anti-vax stance as recently as last week during an appearance before the anti-vaccine advocacy group Children’s Health Defense, which he founded.
Travel is a major vector for the disease. On Sept. 21, for example, the Kansas Department of Health and Environment reported two cases of measles traced to travel outside the state, which had a major outbreak of the disease in 2025.
