Measles in the Northeast: PA and MD cases surge as NYC and DC report single digits
Pennsylvania measles deaths climb to 4
Pennsylvania confirms four measles-related deaths amid a record 693 cases across 38 counties. Dr. Michael Cirigliano provided expert insight.
NEW YORK CITY - The United States is currently facing its most severe measles year in more than three decades.
As measles cases rise nationwide, the Northeast is experiencing both the worst of the outbreaks and the strongest examples of containment.
35-year high
By the numbers:
As of mid-September 2026, the Centers for Disease Control and Prevention (CDC) reported 3,471 confirmed measles cases across 47 jurisdictions in the U.S. The outbreak is a significant jump from the 2,289 cases recorded during the full year of 2025, marking the largest annual number of cases in 35 years.
According to the CDC, 95% of confirmed cases nationally are occurring in individuals who are unvaccinated or have an unknown vaccination status. Additionally, 95% of these cases are directly associated with one of the 39 new outbreaks reported across the country in 2026.
Pennsylvania and Maryland
Local perspective:
Pennsylvania has emerged as a major hot spot for the outbreak. As of late September 2026, the state has recorded at least 767 confirmed measles cases and four measles-related deaths, with infections spreading across 38 different counties.
In mid-September, the Philadelphia Department of Public Health issued warnings regarding a potential exposure at the Children’s Hospital of Philadelphia (CHOP). Just over a week later, another potential exposure was reported at the Philadelphia International Airport.
Measles exposure investigated at CHOP in Philadelphia
The Philadelphia Department of Public Health is investigating a possible measles exposure at Children’s Hospital of Philadelphia, including in the neonatal intensive care unit.
The regional spread has also deeply affected neighboring Maryland, which reported 40 confirmed measles cases by mid-September, primarily clustered in St. Mary’s, Cecil, and Carroll counties.
NYC and Washington D.C.
The other side:
Despite being just hours away from surges in Pennsylvania and Maryland, New York City and Washington D.C. have managed to keep their case counts remarkably low.
D.C. has recorded only one confirmed measles case in 2026, which occurred back in April. However, recognizing the regional threat, DC Health issued a Health Awareness Notice (HAN) on September 14, urging healthcare providers to aggressively screen patients with febrile rash illness and isolate suspected cases immediately.
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Health officials warn of potential measles exposure at Philadelphia Airport
Health officials are warning travelers of a possible measles exposure at Philadelphia International Airport last week, unrelated to recent exposures reported at Children's Hospital of Philadelphia.
NYC Health reported just six confirmed cases of measles as of September 18. Like D.C., New York City is leaning heavily on routine monitoring and localized health alerts to prevent imported cases from igniting a wider community outbreak.
Why the divide?
Dig deeper:
The stark contrast between Pennsylvania's hundreds of cases and the single-digit case counts in D.C. and NYC highlights the localized nature of measles outbreaks. Since the virus is airborne and can remain infectious in the air or on surfaces for up to two hours after an infected person has left the room, experts say it spreads aggressively through under-vaccinated pockets of the population.
Outbreaks in the U.S. typically begin when an infected international traveler enters a community with lower routine MMR vaccination coverage. Once established, the virus rapidly infects those without immunity, which includes infants under 12 months, pregnant women, and immunocompromised individuals.
According to the CDC, maintaining a high baseline of community immunity around 95% vaccination coverage is the strongest defense against this highly contagious virus, explaining how cities like D.C. and NYC have held off the regional surge.
The Source: Information from this article was sourced from the Centers for Disease Control and Prevention (CDC), the Pennsylvania Department of Health, the Philadelphia Department of Public Health, DC Health, and NYC Health.