Dallas Ebola patient Amber Vinson contacted the Centers for Disease Control and Prevention before boarding a commercial flight Monday because she had a slight fever and was cleared to fly, CDC spokesman David Daigle told The Associated Press.
"Vinson was not told that she could not fly," a government spokesperson also told NBC News.
Vinson, the second Dallas nurse to fall ill with the virus after treating the first U.S. patient there, was flown to Atlanta for treatment at Emory University Hospital on Wednesday, after being treated in isolation at Texas Health Presbyterian Hospital in Dallas.
She was part of the team that treated Thomas Eric Duncan, the first patient diagnosed with Ebola in the U.S., at Texas Health Presbyterian before he died there.
Vinson, 29, had been self-monitoring and was reporting her temperature to CDC epidemiology teams routinely.
The unidentified government spokesman told NBC News that Vinson called the CDC on Monday before flying from Cleveland back to DFW on Frontier Airlines Flight 1143, and she reported that she had a temperature of 99.5 degrees.
According to the government spokesperson, when Vinson called in, the staff she talked with looked on the CDC website for guidance. At the time, the category for "uncertain risk" had guidance saying that a person could fly commercially if they did not meet the threshold of a temperature of 100.4.
CDC Director Dr. Tom Frieden had said earlier Wednesday on a phone press briefing that Vinson "should not have traveled on a commercial aircraft."
The government spokesman said he believed Frieden said what he said because it should have been common sense to Vinson that she should not fly with a slight temperature.
Her travel prompted Frontier and several Ohio medical facilities whose employees shared a flight with Vinson to place restrictions on employees as a precautionary measure.
In a statement to his employees on Tuesday, Frontier Airlines' CEO David Siegel announced that he has placed two pilots and four flight attendants on paid leave for 21 days "out of an abundance of caution."
In a joint statement with University Hospital, The Cleveland Clinic and The MetroHealth System said they have placed employees who returned home from a nursing conference on the Oct. 10 Frontier flight from Dallas to Cleveland on paid leave while their health is monitored.
"We are confident that these nurses are at low risk of exposure since we understand that the Dallas nurse did not have symptoms at the time. We have taken this measure as an extra precautionary step for our employees, patients, and visitors," the statement read.