DC health officials issue measles exposure alert tied to transit routes and medical visit sites

Public health alert outlines specific locations and times

District health officials have issued a public alert after confirming a measles case involving an international traveler who moved through multiple locations in the region while potentially contagious. The advisory identifies several transit and community sites where other people may have been exposed during defined time windows in early June 2025.

The exposure notice includes activity at Washington Dulles International Airport and subsequent travel on the Washington metropolitan transit system, along with visits to an educational site in Maryland and a pediatric medical office in Northwest Washington.

Where potential exposures may have occurred

The advisory lists the following potential exposure sites and times:

• Dulles International Airport (Concourse A, transportation to the International Arrivals Building, and baggage claim): June 8, 10:30 a.m. to 1:00 p.m.
• Metrorail: Silver Line from Dulles Airport Station, transfer at Metro Center to the Red Line toward Shady Grove: June 8, 11:30 a.m. to 2:30 p.m.
• Russian School of Mathematics, 8401 Connecticut Ave., Chevy Chase, Maryland: June 8, 3:00 p.m. to 6:00 p.m.
• Metrobus: L8 southbound to Friendship Heights: June 8, 5:00 p.m. to 7:00 p.m.
• Metrobus: H4 westbound to Tenleytown: June 12, 7:30 a.m. to 9:30 a.m.
• MedStar Health Pediatrics in Tenleytown, 4200 Wisconsin Ave. NW, Washington, DC: June 12, 8:00 a.m. to 2:30 p.m.

Why measles exposure investigations focus on transit and indoor settings

Measles spreads through the air when an infected person breathes, coughs, or sneezes. Health officials note that the virus can remain infectious in the air and on surfaces for up to two hours after an infected person leaves an area, which can make enclosed public settings—such as terminals, railcars, buses, and waiting rooms—important to evaluate during exposure investigations.

Measles typically begins with fever and respiratory symptoms, followed days later by a rash that starts on the face and spreads across the body.

Guidance for people who may have been at the listed locations

Officials advise people who were at the locations during the listed times to monitor for symptoms in the days and weeks after exposure. People who are not immune—especially those who have never received a measles-containing vaccine—are advised to contact a health care provider for individualized guidance. Individuals who develop symptoms are advised to isolate and to call ahead before seeking in-person medical care, so facilities can take steps to reduce the risk of spreading infection to other patients and staff.

Health officials also emphasize that people who have received two doses of a measles-containing vaccine, or who were born before 1957, are generally considered protected.