The patient diagnosed with Ebola in Dallas has been identified as a Liberian man named Thomas Eric Duncan, NBC News has confirmed.

He is believed to have flown to the United States via two United Airlines flights, first flying from Brussels to Washington, D.C., and then taking a connecting flight to Dallas-Fort Worth.

United said Wednesday that it believes the patient, whom it did not identify, flew from Brussels to Washington Dulles on Flight 951 on Sept. 20, and then, three hours later, from Washington Dulles to Dallas-Fort Worth on Flight 822 that same day.

The airline, reiterating what health officials have said, said that there was "zero risk of transmission" on any flight Duncan flew, because he didn't begin to show symptons until several days later.

The New York Times reported that Duncan may have become infected in Liberia on Sept. 15, when he helped carry his landlord's gravely ill daughter to the hospital. She died the next day.

Earlier this month, Duncan was completing an employment contract with a shipping company in Liberia's capital city of Monrovia. When that contract expired, he used a visa to travel to Dallas to visit family, well within the virus' 21-day incubation period.

Duncan arrived in Dallas on Sept. 20 and began showing symptoms on Sept. 24, U.S. health officials said Tuesday.

Texas Health Presbyterian Hospital in Dallas said Wednesday that Duncan sought medical care after 10 p.m. Sept. 25 and had only a low-grade fever and abdominal pain.



"His condition did not warrant admission. He also was not exhibiting symptoms specific to Ebola," the hospital said in statement Wednesday. "The patient returned via ambulance on Sunday, Sept. 28, at which time EMS had already identified potential need for isolation. The hospital followed all suggested CDC protocols at that time."

A specimen sent to a state lab in Austin confirmed Tuesday that Duncan had contracted Ebola. Those test results were then confirmed by the Centers for Disease Control and Prevention in Atlanta.

In the days since Duncan left Liberia, his landlord's son, who had helped them carry his sister to the hospital, also died after a short, severe illness, the Times reported. Two other people in Liberia who may have had contact with the woman have also reportedly died.

Meanwhile, health officials in Dallas are monitoring as many as 18 people, including five children and an ambulance crew of three, who have been in contact with Duncan.

The schoolchildren and firefighters are all being isolated at home and will be monitored for 21-days from their date of exposure.

The four schools attended by the five students — Dan D. Rogers Elementary School, L.L. Hotchkiss Elementary School, Sam Tasby Middle School and Emmett J. Conrad High School — all remain open but will be thoroughly cleaned, Dallas Independent School District Superintendent Mike Miles said Wednesday.

Mike Miles, the superintendent of the Dallas Independent School District, said five children are being monitored after coming into contact with a man diagnosed with the Ebola virus. Miles spoke Oct. 1, 2014, during a news conference at Texas Health Presbyterian Hospital in Dallas.

None of those being monitored are currently showing any signs of Ebola, and state and federal health officials say no other suspected cases of Ebola exist in the United States.

NBC 5's Scott Gordon contributed to this report.