Maryland declares measles outbreak in three counties

The Maryland Department of Health has declared a measles outbreak in St. Mary’s, Carroll, and Cecil counties following the identification of 14 new confirmed cases among unvaccinated residents. This brings the total number of confirmed measles cases in the state to 31 this year, with 27 of those occurring since July 15, 2026.

Health officials report that most cases have occurred among household contacts, and there is currently no evidence of widespread community transmission. All 27 cases identified since mid-July were among unvaccinated individuals. Maryland Department of Health Secretary Dr. Meena Seshamani emphasized that while the overall risk remains low for those who are fully vaccinated, the disease is highly contagious.

Medical experts, including infectious disease physician Alexandra Yont, noted that measles is an extremely effective transmitter; for every one infected person, between 10 and 13 unprotected individuals could become ill. Potential complications include pneumonia, which requires hospitalization in approximately 1 in 100 children, and encephalitis, which can lead to permanent brain damage. The mortality rate is estimated between 1% and 2%. Health officials recommend the MMR vaccine be administered at 12–15 months and again at 4–6 years of age.