May 20, 2003. Copyright 2002. Graphic News. All rights reserved.

Scientific Òglobal villageÓ joins forces to fight SARS

LONDON, May 20, Graphic News: Within the first six weeks of the identification of a potentially fatal respiratory infection in China and Vietnam international air travel had spread it around the world.

By mid-March the disease, now dubbed Severe Acute Respiratory Syndrome (SARS), had become a household word and claimed nine lives worldwide. Eight weeks later the SARS death toll had risen to more than 640, with 7,860 people infected in 28 countries (May 19).

This new disease, with no known treatment, was first identified by World Health Organization (WHO) infectious disease specialist, Dr. Carlo Urbani, while treating an American businessman in Hanoi in early February.

Because of Dr. UrbaniÕs early detection, global surveillance was stepped up, new cases were isolated and almost certainly lives were saved. But forty-six-year-old Dr. Urbani, who was president of the organisation Medecins Sans Frontieres when the group was awarded the Nobel Peace Prize, himself became infected and died of SARS in Bangkok on March 29.

Since his death, doctors have used the internet to do a global Òward roundÓ of cases; and researchers in Canada, the United States, Hong Kong, Germany, Britain and the Netherlands have worked together to isolate the SARS pathogen. A detailed study at LondonÕs Imperial College of 1,425 cases based on the first nine weeks of the outbreak in Hong Kong has put the death rate at one in five (20 percent) -- much higher than the WHOÕs original estimate of five percent.

The genome of the virus, SARS-CoV -- a new member of the coronavirus family which causes the common cold -- has been mapped and its rate of mutation has been discovered to be low, unusual for coronas, but encouraging for an effective treatment. The genetic fingerprint of SARS-CoV suggests that drugs already in existence could -- with slight modifications -- be used to combat the killer.

Researchers at the University of LŸbeck in Germany have developed a model for the crystalline structure of an enzyme made by the coronavirus called protease. This key protein is vital to the survival of the virus because it enables it to reproduce after it has hijacked a host cell in an infected person. 

Lead researcher Dr. Rolf Hilgenfeld believes progress towards an effective treatment will be rapid: ÒI think it could be very fast now because we have a very detailed template for the design of new drugs.Ó 

ÒTo turn these into real drugs, including clinical trials and so on, will of course take much longer, probably a couple of years.Ó 

One possible treatment is an anti-viral drug developed by pharmaceutical giant Pfizer and known as AG7088. Currently in clinical trials for the treatment of the common cold, AG7088 is one of several compounds that have shown ÒmoderateÓ but ÒencouragingÓ action against SARS in test tube experiments, said Pfizer vice president Peter B. Corr. AG7088 acts as a protease inhibitor, blocking the enzyme which cuts and shapes genetic material to assemble multiple copies of the SARS virus.

A new WHO study says only 16 of the more than 7,800 people infected worldwide contracted the disease while aboard an aircraft and that all of those cases emerged before airlines began screening passengers for symptoms. The results come as welcome news for the worldÕs airlines, which have suffered a deep slump in traffic, especially in Asia.

Meanwhile, the WHO remains optimistic that isolation and quarantine measures will be enough to stop the spread of SARS.
/ENDS

Sources: Science, World Health Organization