A fever, a cough, red and watery eyes, and then a blotchy rash spreading from the hairline down. For families in parts of Pennsylvania, these symptoms have become alarmingly familiar this year. The state’s measles outbreak has now passed 1,000 confirmed cases, and doctors say both the official count and the spread are likely to keep growing.
Key Takeaways
- As of October 5, 2026, Pennsylvania has confirmed 1,004 measles cases in 39 counties since the outbreak began in late April. Of those, 198 people were hospitalized and 5 died.
- Lancaster County is the epicenter, with 391 cases. Most of the spread has been in close-knit communities with low vaccination rates.
- Experts believe many cases are going uncounted, because some sick people never see a doctor or get tested.
- Fewer than 1% of cases were in people fully vaccinated with two doses of MMR. Two doses are about 97% effective at preventing measles.
- Nationally, the U.S. has recorded more than 3,800 measles cases in 2026, the highest total since 1991.
What’s happening now
The Pennsylvania Department of Health reported 27 new cases between October 2 and October 5 alone. Nearly 20% of identified patients have needed hospital care, higher than the roughly 11% seen nationally.
Five people have died of measles-related causes. Two were unvaccinated adults, ages 18 and 40. Two were infants too young to be vaccinated. The fifth was an unvaccinated Lancaster County resident. That’s the most measles deaths tied to a single U.S. outbreak in more than three decades.
The outbreak is now among the largest in the U.S. in decades. It rivals the recent major outbreaks in Texas (about 990 cases) and South Carolina (997), though it’s still smaller than Philadelphia’s 1990–91 epidemic of roughly 1,400 cases.
Why the real number is likely higher
Public health experts say the official count captures only part of the outbreak. Much of the spread has been in Amish and Mennonite communities, where vaccination rates are low, families are large, and people often seek medical care only when illness becomes severe. Mild cases that never reach a doctor are never tested or reported.
Several clues point to undercounting. About two-thirds of reported cases are in adults, which is unusual for measles, a disease that typically hits children hardest. Researchers suspect many children with milder illness simply aren’t being taken to a doctor. The high hospitalization rate suggests the same thing: if mostly severe cases are being counted, the share who end up hospitalized looks larger than it really is.
Contact tracing has also been difficult. Local health officials have described people not answering calls or not following the 21-day home quarantine recommended after exposure. Infectious disease experts, including Dr. Paul Offit of Children’s Hospital of Philadelphia, have warned that the outbreak is likely considerably worse than the confirmed numbers show.
What to do to protect yourself and your family
Measles is one of the most contagious diseases known. The virus can linger in the air for up to two hours after an infected person leaves a room, and people are contagious from four days before the rash appears until four days after.
- Check your vaccination records. Two doses of MMR (measles, mumps, rubella) vaccine give about 97% protection for life. Adults who aren’t sure they’ve had two doses, or who have had only one, should ask their doctor or pharmacist. A blood test can check immunity, but getting another dose is safe if records can’t be found.
- Know who’s generally considered protected. Adults born before 1957 are generally considered immune because they were likely exposed as children. Check with your doctor if you’re unsure or have a weakened immune system.
- Protect babies. Infants usually get their first MMR dose at 12 to 15 months. In outbreak areas or before international travel, doctors may recommend an early dose from 6 months of age.
- Know the symptoms. Watch for high fever, cough, runny nose and red, watery eyes, followed 3 to 5 days later by a rash that starts on the face and spreads downward. Symptoms usually begin 7 to 21 days after exposure.
- Call ahead before seeking care. If you suspect measles, call your doctor’s office or the emergency room before you arrive so staff can keep you from exposing others in the waiting room.
- Be extra cautious if you’re pregnant or have a weakened immune system. The MMR vaccine isn’t given during pregnancy, and measles can be especially dangerous for these groups. Talk to your doctor about your immunity and what to do if you’re exposed.
Pennsylvania residents with questions can call the state health hotline at 877-PA-HEALTH (877-724-3258).
The bigger picture
Kindergarten MMR vaccination rates in the U.S. have slipped to 92.4% for the 2025–26 school year, down from 95.2% before the pandemic. About 95% coverage is needed to stop measles from spreading in a community. As more pockets of the country fall below that level, health officials warn that large outbreaks like Pennsylvania’s are becoming harder to contain.
This isn’t a substitute for medical advice. Talk to your doctor about your vaccination status.
Sources:
- Pennsylvania Department of Health. Statewide update on measles outbreak as cases reach 1,004 in 39 counties. October 5, 2026.
- ABC News. Measles cases surpass 1,000 in Pennsylvania. October 2026.
- STAT. How big is Pennsylvania’s measles outbreak? October 2, 2026.
- Philadelphia Inquirer. Pennsylvania has logged 1,000 measles cases. October 5, 2026.