A measles patient traveled from New York to Washington, DC, on an Amtrak train on the evening of March 19, exposing people along the heavily traveled route to the highly infectious disease.

Washington, D.C. health officials are warning of a possible measles exposure on a recent Amtrak Northeast Regional train. DC Health said it was notified of a confirmed case of measles by a person who visited multiple locations in the capital city while contagious,