The Centers for Disease Control and Prevention confirmed on Tuesday the first case of Ebola in a critically ill patient diagnosed in a U.S. hospital.

The patient — who has been isolated since his symptoms were recognized — is an unnamed man in intensive care at Texas Health Presbyterian hospital in Dallas.

Hospital workers noted his case because of his symptoms and recent travel history. It is not known whether he has infected others, although CDC officials are tracing his contacts.

The man left Liberia Sept. 19 and arrived in the USA the next day but had no symptoms when leaving Africa or arriving here, said Thomas Frieden, the CDC director. The patient became sick Sept. 24, and he sought care two days later. He was sent home but returned to a hospital and was admitted Sept. 28. Frieden did not reveal the man’s nationality but said he came to the USA to visit relatives.

Frieden said there is no danger of the sort of widespread outbreak seen in West Africa.

“This is the first case of Ebola diagnosed in the U.S. and the first strain of this Ebola diagnosed outside of Africa,” Frieden said. “I have no doubt that we will control this case of Ebola so that it does not spread widely in this country. It is certainly possible that someone who has had contact with this patient could develop Ebola, but there is no doubt in my mind that we will stop it here.”