There is no known cure or effective treatment for Severe Acute Respiratory Syndrome, a pneumonia-like illness that the World Health Organization says has infected nearly 5,000 people in 26 countries, mostly in Asia. Public health officials are hoping to keep SARS from becoming a full-blown epidemic.
SARS is what the head of the U.S. National Institute of Allergy and Infectious Diseases, Anthony Fauci, called an "evolving epidemic."
In an interview on the ABC television program This Week, Dr. Fauci said it is very hard to predict which way the epidemic is going to go.
"Whether it is going to continue to escalate, whether it is going to plateau, go down and go back up. So, I think it would be quite correct to say it is not under control right now," he said.
Dr. Fauci said he is skeptical whether SARS will be completely eliminated. "I think the important thing is to get it under control to prevent that domino effect of expansion that from one contact to another, which we have seen in a very, very serious way in Hong Kong and other Asia countries," he said.
The pneumonia-like illness, which originated in China, is caused by a virus. It appears to have jumped from animals to humans. SARS kills approximately six percent of those who become infected with the disease.
So far, all public health workers can do to stem the spread of SARS is to isolate sick individuals and those who have been exposed to the virus.
Julie Gerberding, who head the Centers for Disease Control and Prevention in Atlanta, Georgia, is doubtful screening air passengers flying from Asia to other parts of the world will stop the spread of the virus.
"The problem is that most people who have been exposed to SARS and travel are not actually sick. So, you are not going to pick them up at the border," he said.
Dr. Gerberding, who made her comments on the television program Fox News Sunday, said it takes about 10 days for individuals infected with SARS to show symptoms of the disease.
The World Health Organization has issued an advisory urging travelers not to go to China. Dr. Gerberding said she would heed the warning until there is more information about where SARS is concentrated.