Chester County's confirmed measles cases have climbed to 65, up from 41 on Aug. 25, as Pennsylvania's outbreak has grown to 676 infections across 37 counties with two deaths.
The state Department of Health reported 52 new cases statewide since Sept. 9, 6abc reported Saturday, Sept. 12. Chester County is now designated a county with community transmission, meaning the virus is spreading locally rather than through isolated, traceable contacts.
The 24-case jump in Chester County over 17 days comes as 124 people statewide have been hospitalized and two unvaccinated Lancaster County residents have died. Those are the first measles deaths in Pennsylvania in 35 years, according to LancasterOnline. The state used the term "measles-associated," which it applies when measles is present but the official cause of death is still under investigation.
Lancaster County leads the state with 295 cases. Mifflin County follows with 75. Chester County ranks third, according to PennLive.
More than 99% of people infected in this outbreak were not vaccinated, state Health Secretary Dr. Debra Bogen said. Four vaccinated individuals have tested positive statewide, none of whom were hospitalized.
"Getting fully vaccinated is your best protection against the measles virus," Bogen said. "We are not waiting for Pennsylvanians to come to us."
Thirty percent of the state's cases involve people younger than 18, according to pediatrician Dr. Elana McDonald, who spoke to 6abc. She attributed the spread to misinformation driving vaccine hesitancy.
Early doses advised for infants
Because Chester County has active community transmission, the state now advises parents of infants 6 through 11 months old to get an early "dose zero" of the measles, mumps and rubella (MMR) vaccine, in addition to the two routine childhood doses, the Pittsburgh Post-Gazette reported. Children older than 1 who have not started the MMR series should get two doses at least 28 days apart.
Two doses of the MMR vaccine are 97% effective at preventing measles, according to the Department of Health.
Chester County Health Department Director Jeanne Franklin told City & State PA on Aug. 27 that the disease had been so rare that her lead nurse had just seen her first case despite decades of experience. Franklin's team had administered more than 350 MMR doses at that time.
Statewide, health officials have given nearly 4,300 MMR vaccinations at 130 pop-up clinics since the outbreak began in late April, MyChesCo reported. Providers administered more than 46,000 MMR doses in August, nearly double the typical monthly average of 25,000.
How to get vaccinated
Residents seeking an MMR vaccine can call the Chester County Health Department at 610-344-6225 to ask about local availability. The state hotline is 877-724-3258.
The Department of Health lists vaccination sites and tracks the outbreak at pa.gov/measles. Dozens of additional pop-up clinics are planned statewide based on community demand.
