CDC chief: Ebola 'could arrive in the U.S.'

The Ebola crisis in West Africa is "definitely not under control," according to a top Centers for Disease Control official who concedes it's possible the deadly, incurable virus could come to U.S. shores.

Stephan Monroe, deputy director of the National Center for Emerging and Zoonotic Infectious Diseases at the CDC, told CBS News the worst Ebola outbreak in history – with 1,323 cases recorded in Guinea, Liberia, Sierra Leone and Nigeria and 729 deaths – is "rapidly evolving."

"Theoretically, the virus could arrive in the United States," he said.

He said the CDC, consequently, has issued a nationwide health alert to health-care providers in the U.S., with instructions to isolate anyone suspected of being infected.

The CDC instructs that "if someone presents with symptoms that are compatible with Ebola virus, to ask them about recent travel history, and if they do have a travel history and potential exposure, that they put those people into isolation and request specimens for diagnostic testing."

Monroe offered a word of reassurance, however, noting "the health care system in the U.S. is much better isolation facilities and infection control."

"So, we're fairly comfortable that if a patient were identified here in the U.S., that they would be rapidly isolated and that the normal kinds of barrier nursing precautions that would be in place would prevent spread even before the person was confirmed to be a case of Ebola."

WJLA-TV in Washington, D.C., reported doctors are checking passengers at airports in the affected West African countries.

In Charlotte, N.C., the station reported, a hospital emergency room was closed Wednesday while doctors cleared a patient who had recently returned from West Africa.

An analyst in the WJLA reported echoed Monroe's admission that the virus could come to the U.S.

"I would not be surprised if we see isolated cases arrive here, because you can have no symptoms for three weeks after you've been infected," he said. "But those cases would not spread it around the country. We have good hospitals and good infection control."