Genetic testing of animals sold as delicacies in a southern Chinese market confirms suspicions that the SARS virus jumped from animals to people, Chinese researchers said today.
The researchers found clear differences between the animal and human versions of the virus, but said they were minor enough to show that SARS jumped from animals, as influenza and other viruses have done.
"It's a landmark discovery," said Dr Kathryn Holmes of the University of Colorado Health Sciences Center, a leading expert on the coronavirus family that SARS belong to. "The question that everyone has had is, 'how did this virus appear in the human population?'" she added. "This is the first major clue about where the contact might have come from."
Severe Acute Respiratory Syndrome emerged in southern China last November. Its symptoms include severe pneumonia. Between November and May SARS infected an estimated 8,500 people in 30 countries, killing more than 800. It spread as far as Toronto, killing 41 people in Canada.
SARS had never been seen before and it took several months to determine that it was caused by a coronavirus, a member of a family of viruses that causes cold-like symptoms in people and a range of diseases in animals. But the SARS coronavirus is genetically unique and the search was on to find its source.
Researchers at the University of Hong Kong tested eight animals taken from a market in Shenzhen. They also tested 95 workers at the market and patients hospitalized for diseases other than SARS.
The lead suspect was a palm civet, a raccoon-like animal valued as a delicacy. They also tested other animals including a raccoon dog and a ferret badger.