United States: Measles Cases Reach 4,410 as Pennsylvania Outbreak Grows

October 17, 2026 — The US has now recorded 4,410 confirmed measles cases this year, according to the Centers for Disease Control and Prevention, up 330 in one week. Cases have been reported in 47 jurisdictions, and Pennsylvania’s outbreak, the largest in the country, has grown to more than 1,200 cases.

The latest figures

National count: 4,410 confirmed cases as of October 15, 2026, including 18 among international visitors. About 96% are linked to outbreaks, and 42 new outbreaks have been reported this year (CDC).
Hospitalizations: 451 nationwide this year, according to Al Jazeera.
Deaths: The CDC lists 2 deaths in 2026 and notes the figure may change. Pennsylvania officials have confirmed five measles-associated deaths in the state and are investigating a sixth, Al Jazeera reports.
Pennsylvania: 1,222 cases across 42 counties as of Wednesday, October 14, with 86 new cases since October 9 and 225 hospitalizations. The CDC is sending an Epidemic Intelligence Service investigator at the state’s request.
New York: A state disaster order, in effect until November 4, widens who can give vaccines and lets nurses order measles testing more easily.
Ages: 42% of cases are aged 5 to 19, 41% are adults and 17% are children under 5.

What it means for airline travelers

The CDC advises talking to a healthcare provider about MMR vaccination, especially before travel; check your and your family’s records before a trip.
Traveling with babies or young children? Check the CDC’s measles pages and talk to your doctor before you fly.
Canadian and other foreign visitors heading to Pennsylvania or New York should check their own government’s travel health advice before the trip.