Anyone who visited the emergency department waiting room at Carroll Hospital in Westminster on the afternoon of Monday, July 13, may have been exposed to measles, the Maryland Department of Health said in a Wednesday announcement.
The warning stems from five confirmed measles cases in Central Maryland residents who recently traveled together to a location in the United States experiencing an active outbreak, according to the department. It is the largest cluster of cases the state has reported this year, pushing Maryland's 2026 total to nine — the most the state has confirmed in a single year since at least 2019, when it recorded five.
The four measles cases Maryland reported earlier in 2026 were all linked to out-of-state or international travel, according to the department's previous announcements. The department has not said where the five residents traveled, beyond describing it as a location in the U.S. with an active outbreak.
Health officials identified the waiting room of the Carroll Hospital Center Emergency Department, at 200 Memorial Ave., as a possible exposure site on July 13 between 2 and 5 p.m. Measles spreads easily through the air, and the virus can linger for up to two hours after an infected person has left an area.
The department said it is working to notify people who may have come into contact with the individuals. To protect the patients' privacy, officials said they would not release additional information about them.
Of the five people who tested positive, only one came to Carroll Hospital, said Sharon Boston, director of public relations for LifeBridge Health, which owns the hospital.
"Upon recognition of a possible measles case, Carroll Hospital staff acted quickly to take precautions to reduce any potential further exposure," Boston said in a statement. "We are taking appropriate action to ensure the health and safety of all those who may have been in contact with this patient."
Boston said the hospital, working with state and local agencies, is notifying patients, team members and others who were in the emergency department that afternoon. Community members seeking a measles vaccine should contact their pediatrician or primary care physician, she said.
Boston also described the hospital's protocol for measles patients. "Because measles is highly contagious and can remain infectious in the air for up to two hours, patients with suspected or confirmed measles are placed under airborne precautions, preferably in an airborne infection isolation room, sometimes referred to as a negative-pressure room," she said. "Healthcare personnel entering the room use a fit-tested, NIOSH-approved N95 or higher-level respirator."
People who were at the hospital during the exposure window should confirm whether they are immune to measles and monitor themselves for symptoms for 21 days, the state health department said. Two doses of a measles-containing vaccine, or being born before 1957, generally confer protection. Those who are not fully vaccinated and may have been exposed are advised to contact a health care provider or the local health department as soon as possible, because post-exposure treatment may be an option.
Early symptoms, according to the department, include a fever above 101 degrees, a runny nose, cough and red, watery eyes, followed one to four days later by a rash that starts on the face and spreads down the body. Symptoms typically appear 10 to 14 days after exposure but can take as long as 21 days. The department advised anyone who develops symptoms to call a provider before going to a waiting room or emergency department so the facility can take steps to prevent further spread.
By the department's count, Maryland recorded three measles cases in 2025, one in 2024 and one in 2023; fewer over three years combined than the nine confirmed so far in 2026.
Full guidance and exposure information on measles is available from the Maryland Department of Health.
This is a developing story, and it will be updated as more information becomes available.
Editor's note: The subheadline has been extended to clarify that only one of the five people who tested positive visited Carroll Hospital. An earlier version of this story had the subheadline “Five Central Maryland residents have tested positive after traveling together to an area with an active outbreak.” The phrase “one of those five visited Carroll Hospital on July 13” has been added.
Photo from Lifebridge Health website.