DALLAS — A Dallas emergency room sent a man with Ebola home last week, even though he told a nurse that he had been in disease-ravaged West Africa, and officials at the hospital are considering if they would have acted differently had the entire medical staff been aware.

The decision by Texas Health Presbyterian Hospital to release the patient, who had recently arrived from Liberia, could have put others at risk of exposure to Ebola before the man went back to the ER a couple of days later when his condition worsened.

A nine-member team of federal health officials was tracking anyone who had close contact with the man after he fell ill on Sept. 24. The group of 12 to 18 people included three members of the ambulance crew that took him to the hospital, as well as a handful of schoolchildren.

They will be checked every day for 21 days, the disease’s incubation period.

“That’s how we’re going to break the chain of transmission, and that’s where our focus has to be,” Dr. Tom Frieden, director of the Centers for Disease Control and Prevention, told The Associated Press Wednesday.