ATLANTA -- Health officials said Wednesday 11 suspected cases of a mysterious flulike illness have emerged in the United States, while on the other side of the world, medical investigators continue to puzzle over how the illness spread in a Hong Kong hotel.
Dr. Julie Gerberding, chief of the Centers for Disease Control and Prevention, said the suspected U.S. cases are people who recently traveled to Asia and developed fever and respiratory problems, matching definitions for the mystery illness, called "severe acute respiratory syndrome," or SARS.
The illness, for which there is no treatment, has caused 14 deaths, including five who died months earlier in an outbreak in China.
The worldwide number of cases totals 264, according to the World Health Organization. Most of those cases are in Hong King, Vietnam and Singapore. The WHO said Wednesday it continues to receive reports about some patients recovering from the illness, which causes severe fever and breathing problems.
"There's a lot we still don't know about this problem," said Gerberding, who added that the CDC is examining new samples that arrived from overseas.
"It's very preliminary to say any individual is a case of SARS," she said. "It is going to take some days to know for sure."
She declined to say where the U.S. cases are, but one of the suspect cases involves a patient from Albuquerque, N.M., who recently returned from Hong Kong. The patient is in a hospital's respiratory isolation unit, New Mexico health officials said Wednesday.
Although more cases could be identified in the United States, people who haven't recently traveled to affected areas in Asia shouldn't worry, Gerberding said.
"We don't want people who haven't traveled to this region to be concerned about this problem, at least at this point in time," she said.
Around the world, labs are examining samples for signs of paramyxovirus after German and Hong Kong health officials reported finding it in case specimens there. WHO said its labs will study other samples to see if the same virus is present.
"There is now a clue about what might be causing this," said Dr. David Heymann, WHO communicable diseases chief. "This clue will make it easier to diagnose patients."
But Gerberding and other experts cautioned it's too soon to be sure this is the culprit behind the mystery illness.
Paramyxovirus is part of a family of viruses that include respiratory syncytical virus and parainfluenza viruses and those that cause such common childhood illnesses as mumps and measles.
"My suspicion is it may be a new virus within that family," said Dr. Larry Anderson, a CDC virus expert.