Pennsylvania's measles outbreak has nearly doubled since mid-August, reaching 460 confirmed cases across 31 counties as Colonial School District students head back to class Monday, Aug. 31.
Three cases have been confirmed in Montgomery County so far in 2026, though health officials have not released the locations or timing of those cases, Glenside Local reported Saturday, Aug. 29.
Roughly half of the state's 460 cases have been in Lancaster County, where two "measles-associated" deaths prompted Gov. Josh Shapiro to outline a statewide response strategy on Tuesday, Aug. 25. Those deaths were the first measles-associated fatalities in Pennsylvania in 35 years, according to TechTimes.
Both victims were unvaccinated.
Death classification questioned
The Lancaster County coroner told TribLive on Thursday, Aug. 27, that his office had not recorded any measles deaths. He later acknowledged measles was listed as a contributing condition on an infant's death certificate.
"We don't consider that a measles death," the coroner said, as Glenside Local reported.
The Pennsylvania Department of Health (DOH) said one of the two deaths involved an infant whose cause of death was a ruptured spleen. The department uses "measles-associated" when evidence of the disease is present but the medical certifier has not determined measles to be the immediate cause.
Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, criticized the state's messaging in a Substack article published Saturday, Aug. 29. He wrote that the DOH withheld details that could identify the victims, citing privacy, even though state law allows disclosure to prevent further deaths during an active outbreak.
Dr. Adam Ratner, a pediatric infectious disease physician, told 6ABC that it is premature to rule out measles as a factor. He said measles-associated deaths do not occur when the virus is not circulating.
Shapiro speaks in Upper Moreland
Shapiro addressed the outbreak Friday, Aug. 28, during a visit to Upper Moreland Township in Montgomery County.
"This is obviously a deeply serious measles outbreak that we are dealing with all across the commonwealth of Pennsylvania and since my comments on Tuesday that you referenced, the situation has gotten much worse," Shapiro said.
He said the DOH had shared all the information state law permits and that the two Lancaster County deaths were measles-related. In a Tuesday, Aug. 25, post on X, Shapiro called the illness completely preventable and urged parents to make sure their families are fully vaccinated.
What local families should know
Colonial School District's first day is Monday, Aug. 31, for kindergarten, sixth grade and ninth grade. All other grades report Tuesday, Sept. 1.
Under Pennsylvania rules, unvaccinated students who are exposed to measles in school can be excluded for up to 21 days, according to Medical Daily. A vaccination exemption allows a child to enroll without the shot, but it does not prevent exclusion after a confirmed case in the building.
The state launched an online tool Aug. 4 that lets parents check measles, mumps and rubella (MMR) vaccination rates at individual schools for the first time, as the Times Herald reported. More than half of reporting schools meet the 95% MMR threshold for kindergartners. The DOH also issued guidance in late June allowing health care providers to vaccinate infants as young as 6 months during the outbreak.
The two-dose MMR vaccine is 97% effective at preventing measles, according to the DOH.
How to report symptoms
The Montgomery County Office of Public Health says about 90% of non-immune people who have close contact with an infected person will contract measles. Symptoms appear 7 to 14 days after exposure.
Anyone who suspects exposure and develops symptoms should call a health care provider or the Montgomery County Office of Public Health at 610-278-5117 before visiting a medical facility. The state's measles hotline is 877-724-3258.
