Hicks was likely contagious with the virus as early as Monday, but without symptoms until Wednesday. And she was in close contact with several White House staff in close quarters, said Dr. Jonathan Reiner, a CNN medical analyst and cardiologist at George Washington Medical Center.

Hicks rode on Marine One — in this case a small helicopter — with the President and other staffers, too. “Everyone on that aircraft has been exposed to the virus, we know that with clarity,” Reiner said…

“The entire staff who traveled with the President this week should be quarantined for 14 days, the President of the United States should be quarantining for 14 days,” Reiner said.