ATLANTA – Federal health officials said Sunday they are analyzing samples from a mysterious pneumonia-like illness that has afflicted more than 150 people in seven countries and caused nine deaths.
They are also handing out information cards to travelers from countries where the disease has appeared, asking them to see a doctor if they experience symptoms such as high fever or respiratory problems.
"This is an evolving problem," Dr. Julie Gerberding, director of the Center for Disease Control and Prevention, said Sunday. "We want to keep our mind to new information as we learn more."
No cases had been identified Sunday in the United States, although the CDC had received calls about potential cases that are being investigated, Gerberding said.
Two people who had been in this country are believed to have developed the mysterious illness. A doctor from Singapore was taken off a New York-to-Singapore flight in Germany on Saturday and quarantined, and a woman, hospitalized in Canada with similar symptoms, had traveled to Atlanta on business shortly before becoming ill.
Little is known about the disease, called Severe Acute Respiratory Syndrome.
More than a week after it began appearing, health officials still didn't know if it was a virus or bacteria. CDC officials said it appears to affect only those in close contact with infected people -- family members and health care workers -- from afflicted areas, countries that include China, Indonesia, Philippines, Singapore, Thailand and Vietnam.
Gerberding said doctors are unsure whether antibiotics or antiviral drugs have an effect on the disease since they have not been consistently used in the areas with the most cases.
Although the CDC is keeping "an open mind" about bioterrorism, Gerberding said the mystery illness appears to be naturally occurring.
"Right now, it's an issue for travelers returning from parts of Asia, we're not seeing a spread" in the United States, Gerberding said Sunday. "We've taken steps to put the health system on alert."
Gerberding said the CDC is working to get more samples for its labs to analyze. Tests could take several days, but officials said they hope to have initial results ready by early this week.
The CDC's emergency operations center -- which previously handled the 2001 anthrax attacks and last year's explosion of the West Nile virus -- has been activated to coordinate a multinational effort in learning about the new disease.