The Maryland Department of Health has declared a measles outbreak in St. Mary’s, Carroll and Cecil counties following the confirmation of 14 new cases among unvaccinated residents.
No public exposure locations have been identified in connection with the new cases. Health officials said there is currently no evidence of widespread community transmission, as most infections occurred among household contacts.
Maryland has recorded 31 confirmed measles cases so far in 2026, including 27 since July 15. All 27 recent cases involved unvaccinated residents and were reported in St. Mary’s County, with 13 cases; Carroll County, with eight; Cecil County, with five; and Charles County, with one.
The four cases confirmed before July 15 involved residents of Anne Arundel, Baltimore and Prince George’s counties. No cases have been reported in Montgomery County this year.
“Measles is highly contagious and we are actively working with healthcare professionals and local health departments to support impacted communities, respond to cases and mitigate further spread,” Maryland Department of Health Secretary Dr. Meena Seshamani said. “The overall risk remains low if you are fully vaccinated.”
According to health officials, someone who is not protected against measles has a 90% chance of becoming infected if exposed. The measles, mumps and rubella vaccine is routinely recommended for children at 12 to 15 months of age, followed by a second dose between ages 4 and 6. An early dose may be considered for infants between 6 and 11 months who live in or are traveling to an outbreak area.
Adults are generally recommended to have at least one documented MMR dose, while some people at higher risk are advised to receive two doses if they do not have other evidence of immunity.
The state is working with local health departments in the affected counties to expand vaccination opportunities and provide information about measles. More than 106,000 MMR vaccinations have been administered in Maryland during 2026, including more than 24,000 since July 1.
Health officials are encouraging residents to contact their healthcare providers or review their immunization records to determine whether they are up to date on the MMR vaccine.
