Top health officials have confirmed the first case of Ebola diagnosed in the United States, saying a patient who recently travelled to Liberia has the disease and is being treated in isolation at a Texas hospital.

The most recent outbreak of Ebola has claimed more than 3,000 lives in West Africa, and Liberia has been particularly hard hit.

Edward Goodman, an epidemiologist at Texas Health Presbyterian Hospital in Dallas, said Tuesday the patient is ill and being seen by "highly trained, competent specialists" under intensive care.

Doctors and health officials couldn't release more details about the patient, but they did note that there are no other known cases in Texas.

According to Dr. Thomas Frieden, director of the U.S. Centers for Disease Control, the patient left Liberia on Sept. 19 and arrived in the U.S. the next day.


Dr. Tom Frieden, director of the U.S. Centers for Disease Control, says a patient at Texas Health Presbyterian Hospital has tested positive for Ebola, the first case of the disease to be diagnosed in the United States. (John Bazemore/Associated Press)

Ebola symptoms can include fever, muscle pain, vomiting and bleeding, and can appear as long as 21 days after exposure to the virus. The disease is not contagious until symptoms begin, and it takes close contact with bodily fluids to spread.

The patient had "no symptoms" when leaving Liberia or entering the U.S., but began to develop symptoms around Sept. 24. Two days later the patient sought care, Frieden said, and was admitted to hospital on Sunday.

Health officials are tracing the patient's contacts, but Frieden reiterated that Ebola does not spread from someone who is not infectious. 

"It does not spread from someone who doesn't have fever and other symptoms," he said. 

Testing for Ebola is highly accurate, the CDC director said after confirming the diagnosis.  

"The bottom line here is I have no doubt that we will control this importation, or this case of Ebola, so that it does not spread widely in this country," he said, adding that it is possible that someone who had contact with the patient could develop Ebola.

"But there is no doubt in my mind that we will stop it here."  

'Cast the net widely'

When asked about how many people may have been exposed, Frieden couldn't yet offer specifics, but said a "handful" was likely the right characterization. Several family members and possibly some community members may have been exposed, he said. 

"Our approach in this kind of case is to cast the net widely to ensure that we're identifying even people who may not have had direct contact, so that we're erring on the side of safety," he said. 

Dr. David Lakey, commissioner of the Texas Department of State Health Services, also addressed reporters, saying "thoughts and prayers" are with the patient and family members.

Lakey said there are "no other suspected cases in the state of Texas at this time" but that his department is closely monitoring the situation.

Frieden also noted the importance of efforts to help with Ebola in West Africa.

"We are invested in ensuring that the disease is controlled in Africa, but also in ensuring that where there are patients in this country who become ill, they're immediately isolated and we do the tried and true core public health interventions that stop the spread of Ebola." 

Dr. Gregory Taylor, Canada's chief public health officer, said in a statement Tuesday night that Canada is "aware of the individual with Ebola" in the U.S.

"The information we have to date is that the individual did not travel through Canada and was not symptomatic, and therefore not contagious, during their travel to the United States."

He reiterated the message of U.S. health officials, saying that Ebola doesn't spread easily from person to person and requires "direct contact with an individual with symptoms."

Taylor, who was recently made permanent chief of the public health agency, said the federal government, provinces and hospitals have systems and procedures in place to track and limit the spread of infectious diseases. 

There have been no confirmed cases of Ebola ever being contracted in the United States, but several American aid workers in West Africa have been brought back for treatment for the disease.

Through the summer, U.S. health officials prepared for the possibility that a traveller could unknowingly arrive with the infection. Health authorities have advised hospitals on how to prevent the virus from spreading within their facilities.

People boarding planes in the outbreak zone are checked for fever, but that does not guarantee that an infected person won't get through. Ebola is not contagious until symptoms begin, and has an incubation period of up to 21 days. It takes close contact with bodily fluids to spread.

ebola CDC facts

A graphic posted on Twitter by the U.S. Centers for Disease Control and Prevention explains how Ebola is spread by direct contact with bodily fluids of a sick person or exposure to contaminated objects. (CDC/Twitter)

With files from Reuters and The Associated Press