"This is now a global epidemic and potentially a global pandemic" if it is not quickly brought under control, said Dr. Julie Gerberding, head of the U.S. Centers for Disease Control and Prevention.
The CDC yesterday said it was monitoring 51 possible cases in 21 states of the disease known as severe acute respiratory syndrome, or SARS, and that there have been no fatalities in this country.
The CDC's list did not include two new suspected cases in New York City as of yesterday.
"We have no evidence that these infections were acquired locally," said city Health Department. epidemiologist Dr. Michael Phillips. "Both likely acquired it while traveling in southeast Asia. Both had been in Hong Kong.
"Currently, both patients are doing well," he said, adding that the other four suspected cases "essentially resolved their illness."
The latest CDC figure includes the first two suspected cases in New York outside the city - in upstate Jefferson County.
A mother and baby who spent time in China with a brief layover in Hong Kong became ill and "are both fine now," said a state Health Department spokeswoman.
Around the world, more than 1,400 people have been reported with SARS in 12 countries, and more than 50 have died, mainly in southeast Asia.
Meanwhile, in a warning that suggests for the first time that the disease can spread on airplanes, the World Health Organization yesterday advised that airlines flying out of cities hit hard by SARS should ask passengers who are checking in about any signs of sickness.
