First confirmed case of Ebola confirmed in the United States: CDC

The United States now has one confirmed case of Ebola, the Centers for Disease Control and Prevention said on Tuesday, marking the first domestic appearance of the deadly virus that has ravaged swaths of continental Africa.

The as-yet unidentified patient is located in Dallas, officials say, effectively confirming a statement issued on Monday by Texas Health Presbyterian Hospital of Dallas. The organization said that an unnamed patient was being tested for Ebola and had been placed in "strict isolation" due to the patient's symptoms and recent travel history.

In a press conference, CDC Director Tom Frieden said the patient in question had been traveling in Liberia, where he may have contracted the disease. He returned to the United States on the 20th of September, after which he sought care.

Frieden attempted to assuage concerns about Ebola's contagious effect, saying that the virus was only spread through direct contact, and was not airborne. He vowed that officials would contain a potential spread.

"It is certainly possible that someone who had contact with this individual...could develop Ebola in the coming weeks," Frieden said, but added that "there is no doubt in my mind that we will stop it here," Frieden said.

Read MoreCDC: Working to identify anyone who had contact with sick patient

In response to a question, Frieden added that "a handful" of people, including family members, may have been exposed to the patient prior to his seeking treatment.

In early September, four U.S. aid workers treating the outbreak in Africa were diagnosed there, and transported back to the U.S. for treatment after falling ill. This case, however, is the first known in which a citizen was stricken by the virus and diagnosed domestically.

Read MoreEbola: A closer look at this 'frightening disease'

The recent outbreak is widely considered by experts to be the deadliest in history. In recent days, global health professionals have warned that the strain of Ebola was becoming more virulent, and that governments around the world needed to step up their response. The World Health Organization has estimated that at least 3,000 have died since the first outbreak was identified in Guinea six months ago, and more than 6,500 cases have been confirmed.

Read More 100 doses of Ebola drug available: Sarepta CEO

Last week, the head of Doctors Without Borders told the United Nations that the virus "is winning." Separately, the CDC warned that between 550,000 and 1.4 million people in West Africa could be infected with Ebola by January 2015. Sierra Leone, Liberia and Guinea are among the countries most badly affected by the virus.

Read MoreEbola by the numbers

News of the virus' appearance sent the share prices of key biotechnology and pharmaceutical companies skyrocketing in after-hours trading. BioCryst Pharma shot up 15 percent in after-market trading, while Tekmira soared by nearly 17 percent.

Read MoreEbola stocks surge after first US case diagnosed

Edward Goodman, the hospital epidemiologist at Texas Health Presbyterian Hospital Dallas, said in a news conference that believed the patient walked into the hospital on his own for his first visit, and then was taken in by ambulance the second time.

As for other medical facilities in the region, "there's no evidence that he went anywhere else before," Goodman said.

The hospital is "taking every step possible to manage this situation," the doctor said, which includes keeping the patient in "appropriate isolation."

--CNBC's Everett Rosenfeld contributed to this report.