U.S. public health officials are warning Americans not to be complacent about SARS, Severe Acute Respiratory Syndrome, despite the small number of cases in the country. U.S. government laboratories are going through the arduous process of testing anti-viral compounds for effectiveness against the new respiratory disease.
Out of roughly 4,000 SARS cases worldwide, the United States as of Tuesday has less than 40, with no deaths.
But the director of the U.S. government's disease tracking agency, Dr. Julie Gerberding of the Centers for Disease Control, said the low caseload is no reason to be complacent. She warns that continuing SARS transmission in other parts of the world, particularly Hong Kong and China, is reason for vigilance.
"We still have no capacity to predict where it's going or how large it's ultimately going to be. The last thing that we can do at this point in time is relax. This is exactly the time where we need to continue to do what we're doing and learn our lessons from what we are observing in the other countries that are working on this problem," Dr. Gerberding said.
The Coronavirus that causes SARS was identified and genetically mapped in just seven weeks, a record time for an infectious agent. Finding a treatment, however, will take longer. Dr. Gerberding said U.S. government laboratories are poring through their anti-viral databases to see if any drug exists that can stop the virus, but nothing has turned up yet.
"Right now, we don't have any scientific evidence to suggest that any form of specific treatment for SARS is effective. So far we don't have any leads on an anti-viral compound, but if we get any clinically promising compounds, we will, of course, work hard to get them into a clinical trial so that we can check them out. This is not going to happen fast," he said.
In addition to seeking a SARS treatment, U.S. public health officials are trying to understand the biology of this young disease. Why do some people get sicker than others? Why are some more infectious? How long is a patient infectious after acquiring the virus? And what is the long-term prognosis for patients who recover?
An important part of controlling an outbreak is determining its source. World Health Organization experts have traced SARS to China's southern Guangdong Province. But did the virus jump from an animal to people? Dr. Gerberding said that is plausible because the two other known Coronaviruses have been seen in a variety of animals with which many Asians have contact.
But she points out that no scientific evidence supports that theory. Laboratory tests have not yet shown any similarity between the genetic makeup of the SARS virus and known animal or bird viruses.