April 23, 2003
Scientists in search of a SARS cure have narrowed their focus to several dozen drugs that appear to have the best chance of stopping the deadly respiratory virus, but they have abandoned plans to test one of them in people.
The urgent hunt for something that works -- preferably a medicine already on the market or close to it -- was helped by the breakthrough a week ago in decoding the virus's genetic makeup.
While they cannot predict when they will find a treatment, they should know soon if an effective medicine is likely to be in hospitals quickly. If none in testing shows promise in the next few weeks, a treatment may have to be created from scratch, a process that could take at least five years.
For now, severe acute respiratory syndrome treatment amounts to keeping patients isolated and dealing with their symptoms while the infection runs its course.
The drug ribavirin is being used by doctors in Hong Kong and Toronto who are convinced it helps many SARS patients. But U.S. researchers, who have been skeptical all along, shelved a plan to formally test the drug with a careful experiment in people.
Dr. Catherine Laughlin, virology chief at the National Institute of Allergy and Infectious Diseases, said there was simply no evidence it worked. "It has significant toxicity, and there was a real chance you could do more harm than good."
Viruses are much harder to kill than bacteria, and only three dozen antiviral medicines are on the market in the United States. None is specifically aimed at the coronaviruses, the family that includes the SARS virus as well as some that cause common colds.
The best chance of success may be with about 30 drugs not yet approved but already in testing for other purposes. All are aimed at viral processes similar to those in the coronavirus. These include drugs that may prevent the virus from sticking to human cells or that block some of the steps the virus takes to copy itself.
An estimated 4,000 people worldwide have been infected by SARS, and the WHO reports at least 229 deaths, mostly in Asia. The United States reports just 38 probable cases and no deaths.
SARS symptoms include fever, headache, generalized discomfort and body aches. After two to seven days, SARS patients may develop a dry cough and breathing trouble.
NAME GAME: The new coronavirus responsible for the worldwide outbreak of SARS has yet to be officially named.
But some researchers have already weighed in. They want to honor Carlo Urbani, the World Health Organization physician who died of the illness and was among the first to identify it.
L. Andrew Ball, president of the International Committee on Taxonomy of Viruses, which oversees the classification and naming of viruses, said the committee forbids naming them after people. That's because in most cases, he said, the practice lends itself to self-aggrandizement.
-- Information from the Baltimore Sun was used in this report.