Health officials warn of measles exposure at Dulles, Metro sites

A measles exposure alert now stretches across Washington, D.C., and Northern Virginia after health officials said a contagious traveler moved through Dulles International Airport, an Aerotrain connection to baggage claim and multiple Washington Metro Area Transit buses and rail lines between April 23 and April 27.

DC Health said a confirmed measles case in a District resident exposed others at several transit sites during that window. Virginia health officials issued a separate notice after being told that a confirmed case passed through Washington Dulles International Airport on April 23 and April 24. The Virginia Department of Health said the infected traveler was an out-of-state resident who had traveled internationally.

The guidance is clear for anyone who may have been in those locations: watch for fever, runny nose, red eyes, cough and then a rash that can follow several days later. Health officials say the virus can remain in the air for up to two hours after an infected person leaves, and about nine out of 10 susceptible people exposed to measles can become infected if they are not vaccinated. People who are fully vaccinated face much lower risk, but health agencies still urge exposed travelers to verify their MMR status and monitor for symptoms for 21 days. Anyone who is not fully immune should contact a clinician or local health department promptly.

The warning lands during a broader national resurgence. The Centers for Disease Control and Prevention says the United States has recorded 1,814 confirmed measles cases so far in 2026, including 11 among international visitors, and 93 percent of confirmed cases are outbreak-associated. The agency also reports 24 new outbreaks this year and says the country ended 2025 with 2,288 confirmed cases. CDC says measles vaccination coverage must reach at least 95 percent to prevent outbreaks from taking hold.

That threshold matters in a region built on constant movement. A single imported case can move from an international flight to a shuttle, to a baggage connector, to Metro buses and rail cars in a matter of hours, forcing health departments to trace exposure chains across jurisdictional lines. Virginia’s measles guidance says the commonwealth has seen increased measles in 2025 and so far in 2026, driven mostly by travel and household or close-contact spread, but it has not met the outbreak definition of three or more related cases among non-household members. DC Health has already issued similar exposure alerts in February 2026 and June 2025, underscoring how repeatedly travel-related cases can strain local public-health systems.