Pennsylvania Measles Cases Rise to 792 as Outbreak Continues to Spread

Pennsylvania’s measles outbreak has continued to expand, with the state reporting 792 confirmed cases across 39 counties, an increase of 25 cases from the previous update on September 18.

The Pennsylvania Department of Health also reported 155 hospitalizations, up from 150 three days earlier, underscoring the growing impact of the outbreak, which is the largest measles outbreak in the United States so far this year.

Lancaster County remains the hardest-hit area, having recorded more than 300 cases during the outbreak. Other counties reporting substantial numbers include Mifflin County, with 93 cases, and Chester County, with 76.

The outbreak has also been associated with four deaths, according to Pennsylvania health officials. The reported fatalities include two infants in Lancaster County, a 40-year-old woman in Jefferson County and an 18-year-old in Mifflin County. However, the classification of the deaths has become the subject of disagreement between state and federal officials.

The U.S. Centers for Disease Control and Prevention (CDC) has not included the Pennsylvania deaths in its national measles death count while it reviews how measles-associated deaths should be classified. As of September 17, the CDC had recorded 3,471 confirmed measles cases nationwide in 2026.

The resurgence has prompted renewed vaccination efforts across Pennsylvania. State health officials say they have conducted 148 pop-up vaccination clinics in affected communities since April, administering more than 4,800 measles, mumps and rubella (MMR) vaccine doses. More than 46,000 MMR doses were administered by healthcare providers across the state in August alone, compared with a typical monthly average of about 25,000.

The Department of Health is also planning free MMR vaccination services at the Bloomsburg Fair in Columbia County from September 26 through October 3.

Measles is one of the most contagious viral diseases and can cause fever, cough, rash and serious complications, including pneumonia and inflammation of the brain. The disease is largely preventable through vaccination. Pennsylvania health officials say the MMR vaccine is 97% effective at preventing measles after two doses.

The continuing rise in cases has placed Pennsylvania at the center of a broader U.S. measles resurgence, with health authorities continuing to emphasize vaccination, disease surveillance and rapid response to new cases and potential exposures.

Source: Reuters