Ebola is in America

Federal health officials on Tuesday confirmed the first case of Ebola diagnosed in the U.S., a male patient who recently traveled from Liberia to Dallas and a sign of the far-reaching impact of the out-of-control epidemic in West Africa.

The unidentified patient was critically ill and has been in isolation at Texas Health Presbyterian Hospital since Sunday, officials said.

Health authorities have begun tracking down family and friends who may have had close contact with the patient and could be at risk for becoming ill. But officials said there are no other suspected cases in Texas.

The Texas Health Presbyterian Hospital patient traveled from Liberia to September 19 and arrived in the United States on the next day, without showing symptoms of the deadly virus, CDC Director Tom Frieden told reporters in a press conference filmed by NBC News.

The patient, Frieden said, started to show signs of the virus September 24 and then 'sought care' on the 26th. Frieden said two days later the patient was admitted to Texas Health Presbyterian Hospital Dallas and isolated.

Frieden said there was no risk to anyone on the airplane because the patient had no symptoms at the time of the flight.

'From the information that we have now, it does not appear the individual was involved in the response to Ebola, but that's something we'll investigate more,' Frieden told reporters when taking questions.

The patient was in the United States visiting his family, Frieden said.

Frieden would not reveal the patient's nationality.

Asked how many people the patient may have had close contact with in that time period, Frieden said, 'I think a handful is the right characterization.'

Frieden updated President Barack Obama on the patient and the public health investigation, the White House said.

Frieden said he believed the case also marked the first time this strain of Ebola has been diagnosed outside of West Africa.

Officials at Texas Health Presbyterian Hospital say the unidentified patient is being kept in isolation and that the hospital is following Centers for Disease Control recommendations to keep doctors, staff and patients safe.

Dr. Edward Goodman, epidemiologist for Texas Health Presbyterian, said the hospital had a plan for handling Ebola should a suspected case emerge and was 'well prepared' to provide care.

The hospital had announced a day earlier that the patient's symptoms and recent travel indicated a case of Ebola.

The CDC initially embargoed the announcement of the diagnosis until 4:30 p.m. CDT, but then lifted the embargo after several news organizations broke that restriction.

Specimens from the patient were tested by a state lab and confirmed by a separate test by the Centers for Disease Control, said Carrie Williams, spokeswoman for the Texas Department of State Health Services.

'#Dallas patient diagnosed with #Ebola was initially dismissed with prescription for antibiotics,' CBS DFW tweeted.

An investigation is being conducted, KXAS reporter Scott Gordon tweeted.

'Hospital reviewing why patient wasn't properly diagnosed on Friday when he was evaluated and sent home,' Gordon wrote. 'Dismissed with antibiotics.'

Zachary Thompson, director of Dallas County Health & Human Services, said health officials in North Texas are well equipped to care for the patient.

'This is not Africa,' he told Dallas station WFAA. 'We have a great infrastructure to deal with an outbreak.'

Twelve other people in the U.S. have been tested for Ebola since July 27, according to the CDC. All of those tests were negative.

Four American aid workers who became infected while volunteering in West Africa have been treated in special isolation facilities in hospitals in Atlanta and Nebraska, and a U.S. doctor exposed to the virus in Sierra Leone is under observation in a similar facility at the National Institutes of Health.