Cases of measles continue to rise in Pennsylvania, with nearly 117 new cases reported in the last week, but no new cases in the Lehigh Valley.

As of Wednesday, the Pennsylvania Department of Health reported 731 measles cases since the beginning of the year, with about 141 resulting in hospitalizations. Hospitalizations rose dramatically since last week, up nearly 29%.

Four deaths have been reported during the outbreak so far: two in Lancaster County, one in Jefferson County and one in Mifflin County.

Though measles is often associated with children, the majority of cases and hospitalizations have been among adults. Adults between 18 and 49 years of age have been most impacted by this year’s measles outbreak, and made up more than 70% of hospitalizations and about 69% of cases.

Lancaster County continues to lead the state with 308 cases as of Wednesday. Mifflin has become the second-highest at 83 and has the highest rate per capita for the entire state, with roughly 2 cases per 1,000 people.

Cases have been reported in 38 counties, including two in Lehigh County. However, the only counties where there is believed to be active community transmission are Centre, Chester, Clearfield, Indiana, Jefferson, Lancaster, Mifflin, Snyder, Somerset, Union and York counties.

There is no active risk of spread in the Lehigh Valley, nor any of the immediate surrounding counties.

Measles is a highly contagious respiratory disease caused by a viral infection. The virus spreads when an infected person coughs, sneezes or talks, and lingers in the air. Entering a room where someone with measles was two hours prior can lead to contracting the virus. People with measles are infectious up to four days before a rash appears and up to four days afterward.

Across the country, there have been at least 3,294 confirmed cases of measles in 2026, with cases reported in all but five states. The most cases have been reported in South Carolina, Pennsylvania and Utah, according to the Centers for Disease Control and Prevention.

The best protection against measles is getting fully vaccinated. The measles, mumps and rubella vaccine, administered in two doses, boosts a person’s immune system and provides 97% lifetime protection. Less than 1% of measles cases identified in Pennsylvania have been among people who are fully vaccinated.