US Measles Outbreak Tops 1,000 Cases in Pennsylvania, Declared Emergency in New York

Pennsylvania has reported over 1,000 measles cases since the start of 2026, marking the largest outbreak in a single U.S. state since the early 1990s. The state's Department of Health confirmed 1,004 cases as of Monday evening, with 106 new infections identified in the past week alone. The outbreak has spread across 39 of the state's 67 counties, with Lancaster County being the epicenter, recording 391 cases. Nearly 20% of those infected, approximately 198 individuals, have required hospitalization, and over 99% of them were unvaccinated.

The U.S. is experiencing its most severe year for measles cases since 1991, with the Centers for Disease Control and Prevention (CDC) reporting 3,887 cases nationwide by October 2nd. The past two years have seen eight measles-related deaths, a figure higher than in the preceding three decades. A notable characteristic of the Pennsylvania outbreak is the age distribution of those infected; only 32% are under 18, with the largest group being adults aged 25 to 49. This contrasts with pre-vaccination eras when measles primarily affected young children.

Experts attribute this shift to generations of unvaccinated individuals creating a large at-risk adult population. The deceased include a 40-year-old woman with asthma and COPD, an 18-year-old Amish girl who succumbed to a rare neurological complication, and two infants from Lancaster County who were too young to be vaccinated. The article details the tragic case of a 20-year-old Amish woman with leukemia who was denied vaccination due to chemotherapy, subsequently contracting measles and dying from pneumonia. Her family, though not religiously opposed to vaccines, had not vaccinated her due to her compromised immune system.

Pennsylvania Governor Josh Shapiro and U.S. Health Secretary Robert F. Kennedy Jr. have clashed over the handling and reporting of the outbreak's fatalities. Shapiro announced two deaths in August, while Kennedy questioned the official cause of death, suggesting potential political motivations. The Lancaster County Coroner, Dr. Steven Diamantoni, initially attributed one infant's death to spleen rupture, with measles listed as a contributing factor, but later confirmed a second infant's death was directly from measles. The CDC has been criticized for its delayed inclusion of Pennsylvania's reported deaths in its national statistics.

The measles outbreak has extended beyond Pennsylvania, prompting New York Governor Kathy Hochul to declare a state of emergency on Monday due to over 100 cases identified in the state this year. The emergency order expands vaccination authority to paramedics and other healthcare professionals. Ohio has also reported over 200 cases, particularly affecting counties with large Amish communities known for lower vaccination rates. The U.S. was declared measles-free in 2000, but vaccination rates have since fallen below the 95% threshold needed for herd immunity, with kindergarten vaccination rates dropping from 95.2% in 2019-2020 to 92.5% in 2024-2025.

In contrast, Israel registered 3,574 measles cases and 17 deaths between April 2025 and March 2026, according to a study published in Emerging Infectious Diseases. Jerusalem experienced a particularly high incidence, with 1,289 cases and 11 child deaths, many of whom were unvaccinated infants. Vaccination rates in some ultra-Orthodox areas of Jerusalem were as low as 55% in April 2025.