Pennsylvania has confirmed a fifth death associated with measles this year, as the state grapples with a rapidly escalating outbreak that has seen cases more than double since August. The Pennsylvania Department of Health announced Wednesday that an unvaccinated resident of Lancaster County, who had tested positive for measles, had died.

The department confirmed the death was reported to the United States Centers for Disease Control and Prevention (CDC). The state has now recorded 943 confirmed measles cases across 39 counties in 2026, with 40 new cases reported since September 28. At least 176 individuals have been hospitalised due to the illness.

This latest fatality is the third measles-associated death reported in Lancaster County this year. The county, situated in south-central Pennsylvania, is a hub for Amish and Mennonite communities, which have historically experienced lower vaccination rates. Pennsylvania recorded its first two measles-associated deaths in August, marking the first such fatalities in the state in 35 years.

The surge in cases has prompted Governor Josh Shapiro's administration to intensify vaccination efforts and public health outreach. In September, over 53,000 doses of the measles, mumps, and rubella (MMR) vaccine were administered statewide, more than double the usual monthly total. Health experts state that two doses of the MMR vaccine offer approximately 97 percent protection against measles.

The United States is currently experiencing its most severe measles outbreak since 1991. Measles, once declared eliminated in the U.S. in 2000, has resurged in recent years, a trend experts link to increasing vaccine skepticism. The CDC has confirmed two measles-related deaths nationally, though specific locations were not identified.

The state's classification of measles-associated deaths has been a point of contention with federal health officials. Pennsylvania uses the designation for deaths occurring within 30 days of measles symptom onset, unless an unrelated cause is established. This differs from how the CDC may classify deaths, leading to a dispute over the national death count.

Public health officials emphasize the importance of vaccination in preventing measles, a highly contagious viral illness that can lead to serious complications, including pneumonia, encephalitis, and death. The MMR vaccine remains the most effective measure for protection.

As the outbreak continues to spread, health authorities are urging residents to ensure they are vaccinated and to seek medical attention if they suspect they have contracted measles. The ongoing dispute over death classification highlights the challenges in accurately tracking and responding to infectious disease outbreaks.