Students are dismissed from Sam Tasby Middle School on Oct. 1 in Dallas. Officials confirmed that a student, who had contact with the first confirmed Ebola virus patient in the United States, attends classes at the school. (Tom Pennington/Getty Images)

According to officials at United Airlines, the man who has the first case of Ebola to be diagnosed in the United States flew from Brussels through Dulles International Airport and then on to Dallas-Fort Worth on Sept. 20. The airline emphasized that the director of the Centers for Disease Control and Prevention said there is “zero risk of transmission” on any flight, since the man did not develop symptoms until several days after he completed his trip.

The airline released the following statement:

The United States Centers for Disease Control and Prevention (CDC) has informed us that the patient said he flew part of his trip on United. However, without consent, we cannot divulge a traveler’s identity. The director of the CDC has stated there is “zero risk of transmission” on any flight on which the patient flew because he was not symptomatic until several days after his trip and could not have been contagious on the dates he traveled. While the CDC states it is unnecessary for it or the airline to contact others who were on the patient’s flights, United is providing information about the flights United believes the patient took, based on information provided by the CDC. We are ensuring our employees have this information and suggest that any customers who have concerns contact the experts at the CDC for further information.

Airline officials said they believe that the man traveled on the following flights: Brussels to Washington Dulles on Flight 951, and Washington Dulles to Dallas-Fort Worth on Flight 822.

The man has been identified as Thomas Eric Duncan, according to the Associated Press. He  is being treated at a Dallas area hospital. The man told a nurse Friday that he had traveled from Liberia to Texas, but this detail was not shared with everyone treating him, said Mark C. Lester, executive vice president of the health-care system that includes Texas Health Presbyterian Hospital, the Dallas facility treating the man.

The State Department has warned U.S. citizens against non-essential travel to Liberia and Sierra Leone. There are no plans to alter the travel warning in the wake of Duncan’s diagnosis, according to a State Department official.