Pennsylvania's measles outbreak tops 1,300 cases as spread reaches hospital in Hershey

Pennsylvania's measles outbreak, already the largest the United States has recorded in more than three decades, grew again this week, with the state health department reporting 1,338 confirmed cases across 44 counties as of Friday afternoon. That is 21 more cases than the department reported on Wednesday and 78 more than a week earlier, extending an epidemic that began in late April and has not yet run its course.

The Centers for Disease Control and Prevention's own tracking page, last updated Friday, put the nationwide case count at 4,588 as of Thursday for the year across 47 jurisdictions, meaning Pennsylvania alone now accounts for close to 30 percent of every measles case confirmed in the country in 2026. No other state is close.

A slow, steady climb with no clear end

State health officials say 255 people have been hospitalized with measles this year, up from 251 on Wednesday, and five deaths have been formally classified as measles-associated. A sixth death, of a Franklin County resident, remains under review by the department, which has not yet determined whether measles was a contributing cause. The Pennsylvania Department of Health's most recent formal release, issued Wednesday, put the toll at 1,317 cases in 43 counties, 251 hospitalizations and five confirmed deaths, with Washington County newly added to the list of affected counties at that time. Two more counties were added by Friday's count, bringing the total to 44 of the state's 67 counties with at least one confirmed case.

Only four of the 1,338 cases this year, less than 1 percent, involved people who had been vaccinated against measles, according to the department. The department's measles information page, which the state updates on Mondays, Wednesdays and Fridays, continues to urge anyone who has not received two doses of the MMR vaccine to do so, describing vaccination as the only reliable protection against a virus that can remain suspended in the air of a room for up to two hours after an infected person has left it.

Where the outbreak began, and where it has spread

The outbreak traces back to Lancaster County, home to one of the state's largest Plain Anabaptist communities and among the lowest childhood vaccination rates in Pennsylvania. Lancaster County remains the epicenter, though the spread has since reached counties in central and northern Pennsylvania, including Mifflin, Chester, Jefferson, Snyder and Clearfield, before extending further east and west through October. State data compiled earlier in the outbreak found that only about 88.5 percent of kindergartners in Lancaster County had documented immunity to measles in the 2024-25 school year, well short of the roughly 95 percent coverage epidemiologists say is needed to prevent sustained community transmission.

The virus's reach has not been confined to rural communities. On Friday, Penn State Health's Milton S. Hershey Medical Center in Dauphin County took temporary precautions after a possible exposure inside the hospital, relocating potentially exposed patients, distributing masks and routing patients and visitors through controlled pathways, according to a hospital spokesperson cited by CBS affiliate WHP. It was not immediately clear whether anyone exposed at the hospital had tested positive for the virus.

Who is affected

The five confirmed deaths this year include a 20-year-old Lancaster County woman who was unvaccinated and died in late September, and two Lancaster County infants who died earlier in the outbreak. The health department has not publicly detailed the circumstances of the other two confirmed deaths. A sixth possible death, of a 39-year-old Franklin County woman who had been recently diagnosed with measles, is still being reviewed by the state and the county coroner's office and has not yet been added to the official count. Pennsylvania had not recorded a measles death in roughly 35 years before this outbreak began, and officials have said none of the people who died had been vaccinated.

Health officials and physicians outside government have offered differing reads on where the outbreak is heading. State data show new case counts have generally trended downward since a peak early in the outbreak, and the health department's Friday release noted that "case numbers suggest the spread might be slowing." But with cases still appearing in new counties nearly six months in, infectious-disease specialists have cautioned against reading a short-term dip as the outbreak's end, noting that measles can smolder in under-vaccinated communities for many months before burning out entirely.

The department's primary focus remains on stopping the spread of measles across the Commonwealth.

That line, repeated in successive Pennsylvania Department of Health releases since September, has become something close to the state's standing message as the case count has climbed past 1,300.

Federal help and what comes next

The CDC confirmed earlier this month that it was sending additional epidemiologists to Pennsylvania through an Epidemic Assistance, or Epi-Aid, request from the state, supplementing contact tracing and genetic sequencing work that links new cases to the original chain of transmission. The state's disease-control nurses have administered more than 10,000 doses of the MMR vaccine so far this year, split between 223 pop-up clinics in affected communities and routine visits to state health centers, the health department said Wednesday.

The outbreak's duration carries weight beyond Pennsylvania's borders. The Pan American Health Organization has scheduled a review of the United States' measles elimination status for its Regional Verification Commission meeting next month, weighing whether sustained transmission tracing back to a U.S. outbreak that began in January 2025 has run for a full year or longer, the threshold that would cost the country its elimination status. Pennsylvania's outbreak is a separate, more recent chain of transmission that began at the end of April, but its scale now makes it one of the largest pieces of evidence feeding into how federal and regional health officials assess the country's overall measles picture. For now, the state's own dashboard, updated three times a week, remains the most current public accounting of an outbreak that has outlasted most early forecasts for how long it would take to contain.