
Pennsylvania Measles Outbreak Surpasses 1,000 Cases, Marking Largest U.S. Surge in 35 Years
Pennsylvania has recorded over 1,000 confirmed measles cases in 2026, making it the largest outbreak in the United States in more than three decades. The state accounts for all five measles-associated deaths reported in the U.S. this year, with 198 hospitalizations. Over 99% of cases involve unvaccinated individuals, and transmission is concentrated in Lancaster County, which has the highest case count. Public health officials warn that the outbreak is likely to spread to neighboring counties, including Chester and Montgomery, due to low vaccination rates and limited local health infrastructure in many Pennsylvania counties.













