The Pennsylvania Department of Health has identified five confirmed cases of measles in Lancaster County, marking the first cases reported in the state in 2026.
The department said the cases were confirmed Jan. 30 and involve school-aged children and young adults. Health officials described the situation as the first measles outbreak in Pennsylvania this year, defined as three or more linked cases. One of the five cases is not connected to the outbreak and was associated with exposure during travel.
State health officials are urging health care providers to maintain a high level of suspicion for measles in patients who present with fever and rash, particularly among those who are unvaccinated or under-vaccinated. Providers are also being asked to inquire about recent exposures or contact with known measles cases when evaluating patients with symptoms compatible with measles.
To reduce the risk of further spread, the Department of Health said providers should implement infection-prevention measures immediately when measles is suspected. That includes advising patients to call ahead before arriving at a health care facility and involving infection prevention and control staff to follow institution-specific guidance.
The department emphasized that suspected cases must be reported right away to local public health authorities or to the state Department of Health at 877-PA-HEALTH. Providers were instructed not to wait for laboratory confirmation before notifying public health officials if measles is suspected.
Health officials also urged Pennsylvanians to ensure they are up to date on their measles, mumps, and rubella (MMR) vaccinations, calling vaccination the best protection against the highly contagious virus.
Two doses of the MMR vaccine provide about 97% protection against measles, compared with 93% for a single dose, according to the Department of Health. Communities are considered to have herd immunity when at least 95% of residents are vaccinated, which reduces the likelihood of widespread transmission.
The department noted that while population immunity remains high in many U.S. communities, unvaccinated individuals face the greatest risk of infection and can play a disproportionate role in spreading measles to others.
Source: PA Dept of Health