Updated

A U.S. medical worker caring for a patient with severe acute respiratory syndrome likely has become the first U.S. health care worker to contract the new contagious disease that has spread from Asia to the United States and elsewhere, officials said.

Dr. Julie Gerberding, director of the Centers for Disease Control and Prevention, disclosed the health worker case in a speech Tuesday night at the University of California, Berkeley. She did not say where the stricken health care worker lives, only that the person has been added to the list of suspected SARS cases.

"We're confident it will turn out to be a true case," she said.

Separately, officials in North Carolina said they believe a female health care worker there has SARS. They said she came into contact with a SARS patient for about 15 minutes before becoming sick herself. Unlike other U.S. victims, she has not traveled to Asia, where the disease began spreading.

Health care workers were among the early victims of the disease as it began to spread in Asia. Gerberding said the CDC has determined that only about 4 percent of those who contract SARS die — a lower mortality rate than officials initially thought.

"Most people do seem to recover," she said.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, said Wednesday there is not yet a need for a quarantine of SARS patients in this country.

In a televised interview, Fauci noted that President Bush recently signed an executive order adding SARS to the list of diseases for which a quarantine could be imposed.

But when asked if he thought that would happen, Fauci said, "Not necessarily. It's really an evolving situation. Right now, things seem to be under reasonably good control."

"We're prepared to move in that direction," he said, "but that's not right now what we're seeing."

As of Wednesday, there were 154 suspected cases of SARS in the United States and more than 2,600 worldwide.

Health and Human Services Secretary Tommy Thompson cautioned lawmakers that the U.S. number was only suspected cases. "We're not sure all of those will be SARS," Thompson told the House Government Reform Committee on Wednesday. "The probability is they will not be."

Gerberding told the Senate appropriations health subcommittee Tuesday that the CDC is receiving a record number of phone calls from members of the public concerning SARS. She said the volume of daily calls sometimes exceeds 1,500, more than the CDC received even at the peak of the fall 2001 anthrax attacks.

Gerberding said officials are working aggressively with airlines to determine appropriate procedures if a suspected SARS patient is on board a flight, including what protections are needed for workers on the plane and how the plane might be decontaminated.

She also said:

—The CDC is forming a communications team to make sure the agency is doing a good job communicating with the Asian community on SARS. Still, she said, they want to be sensitive to bias, because this is not a disease of Asians but a disease of people who have been in the part of the world where SARS is spreading.

—CDC has three potentially useful tests to diagnose the virus, which CDC suspects is a new form of the coronavirus, which causes the common cold.

She said the U.S. cases, on average, may be less serious than those in other parts of the world because the CDC is using a very broad case definition in hopes of capturing all real cases. Someone doesn't have to have severe pneumonia to be listed as suspect SARS here, she said.

—While the health system in the United States "has risen to the occasion," other nations may not be responding as well to SARS. "It's going to be very difficult to contain it" as it spreads across the globe, she said.