Measles Outbreak Declared In 3 MD Counties: What To Know

Health authorities in Maryland declared a measles outbreak in three counties on Monday, noting that officials recorded over a dozen new cases among unvaccinated residents.

The outbreak was declared in St. Mary’s, Carroll and Cecil counties by the Maryland Department of Health.

The agency said an investigation confirmed 14 new measles cases in Marylanders who were not vaccinated against the highly contagious disease.

Officials did not detail exactly how many of the new cases traced back to each of the three counties.

"There is currently no evidence of widespread community transmission, as most cases occurred among household contacts," the MDH said in a statement. "The department is working with the local health departments in the affected areas to promote opportunities for vaccination."

To date, Maryland has 31 confirmed measles cases in 2026. Of those incidents, 27 cases were confirmed since July 15.

Officials say all 27 occurrences were reported among unvaccinated individuals living in the following counties:

• 13 in St. Mary’s County
• 8 in Carroll County
• 5 in Cecil County
• 1 in Charles County

The MDH said the four cases confirmed before July 15 were tied to residents who lived in Anne Arundel (2), Baltimore (1), and Prince George’s (1) counties.

Unvaccinated individuals have a 90% chance of becoming infected if they are exposed to measles.

Dr. Meena Seshamani, the MDH secretary, said in a statement that the risk remains low for any Marylanders who have already been vaccinated.

Early signs of measles range from a fever exceeding 101 degrees, a rash, and cold-like symptoms such as a runny nose, cough, and red, watery eyes.

While adults are recommended to have at least one measles, mumps, and rubella shot, some residents considered to be at a higher risk are urged to have two doses if they "don't have other evidence of immunity," according to the department.

What To Do If You Were Exposed

Health officials say residents should do the following if they believe they were exposed:

• Find out whether you have been vaccinated for measles or previously had measles. If you have received two doses of a measles-containing vaccine or were born before 1957, you are generally considered protected. To check your immunization status, call your healthcare provider or securely request your records online via My Immunization Record (MyIR).
• If you are not fully vaccinated or otherwise immune to measles (e.g., you already had measles) and you might have been exposed, call your healthcare provider or your local health department as soon as possible to discuss the best next steps for you, as you may qualify for post-exposure treatments.
• People, especially those not fully vaccinated or otherwise immune to measles, who were at this location during the possible exposure times should monitor themselves for any early symptoms of measles for 21 days after the potential exposure.
• Exposed individuals who develop a fever or other symptoms of measles should not go to child care, school, work, or public places and should contact their healthcare provider. They should call their healthcare provider before going to a waiting room or emergency department so that the facility can take measures to prevent measles from spreading to others.

Residents can find additional information about measles online at the MDH's website.