WASHINGTON, Oct. 13  -- The director of the U.S. Centers for Disease Control and Prevention (CDC) said Monday that the first case of Ebola contracted on American soil will change " substantially" how the U.S. approaches infection control efforts.

"We have to rethink the way we address Ebola infection control because even a single infection is unacceptable," CDC Director Tom Frieden told a teleconference.

Frieden said the nurse at Texas Health Presbyterian Hospital in Dallas, who was confirmed to have been infected with Ebola Sunday after providing care for Thomas Eric Duncan, the first Ebola patient in the U.S., is "clinically stable."

He also clarified his remarks Sunday that seemed to suggest it' s the nurse's fault for being infected.

"I spoke about a breach in protocol, and that's what we speak about in public health when we are talking about what needs to happen," said the CDC chief. "Some interpreted that as finding fault with the hospital or the healthcare worker. I'm sorry if that was the impression given. That was certainly not my intention. "

He said every hospital in the U.S. should "think about the possibility of Ebola in anyone" with a fever or other symptoms who has traveled to West Africa in the previous 21 days.

As for the care of Ebola patients, he said the CDC is working closely with hospitals to make "complex" care "simpler and easier with hands-on training, hands-on oversight and monitoring."

The CDC has identified "one and only person" who had contact with the nurse and is monitoring that person for any signs of the disease, Frieden said, adding other people who cared for Duncan, a 42-year-old Liberian who came to the U.S. to visit relatives last month and died last Wednesday, will be actively monitored as well.

The nurse, who has not been identified, reported a low-grade fever Friday night and tested positive for Ebola over the weekend. She is the first person to contract the deadly virus on U.S. soil.