Stöhr says the slaughter of the civets held in captivity is probably necessary, but he warns that reckless culling may eliminate evidence of the origins of the disease.
"The culling may contribute to reducing the risk of SARS transmissions," he said. "But it should not be the only method taken, and it may not even be the most effective way. We need to find out what role these animals play in transmitting the virus. What if we kill all these animals and the virus returns? What animals are we going to kill then?"
Chinese officials, however, are not taking any risks. On Wednesday, according to the Associated Press, animal merchants in Guangzhou watched aghast as government SARS fighters descended on China's largest wildlife market, and hauled off bagfuls of squirming civet cats for slaughter.
The Chinese government says it plans to kill 10,000 civet cats held in captivity before Saturday, before extending the culling to wild civets and other species, including rats.
Wildlife conservationists call the action short-sighted.
"They're scapegoating the animals," said Barry Kent MacKay, the Canadian representative for the Animal Protection Institute in Sacramento, California. "They're looking for something where they can say, 'We've done this, and it's now OK.' But this does not address the real problem: the trade in and use of wildlife species for food."
Experts say China's unhygienic wildlife markets are fertile breeding grounds for dangerous new viruses. The civet cat is seen as a delicacy in southern China. It's one of the main ingredients in the exotic wildlife dish "dragon-tiger-phoenix soup," for which wealthy Chinese will pay a lot of money.
China banned trade in civets and 53 other wild animals in April last year amid sweeping efforts to stop the spread of SARS. But that prohibition was lifted a few months later despite warnings by scientists that animals might still be a health threat.
"Diseases such as SARS, HIV/AIDS, and monkeypox emerged because we increased our contact with wild animals by moving into their habitat, using them as food, or transporting them as part of a global pet and food trade," said Epstein.
Intensive livestock farming next to the Malaysian rain forest saw the emergence of the deadly Nipah virus in 1999.
Some conservationists have also argued that a greater diversity of species serves as a buffer to the spread of infectious diseases, such as the West Nile and Hanta viruses.
Some animal species are less efficient at producing and transmitting the organisms that cause disease, while others are very good at it. By eliminating species that can get infected but don't transmit the virus very well, while leaving species that are better able to transmit the disease, the risk of transmission to humans may actually increase.
"It's possible the same coronavirus that causes SARS may be carried by animals other than civet cats," said Epstein. "These animals may be better able to transmit disease and so by eradicating civets, according to this theory, we may potentially increase the risk for human infection."
Epstein believes emphasis should be placed on preventing disease exposure and transmission. Simple steps, like excluding wildlife from farms and using fences and screens, can help prevent disease transmission to domestic animals and even humans.
Meanwhile, MacKay, who lives near Toronto and experienced SARS first hand when the epidemic jumped from Asia to Canada last spring, warns of a ticking time bomb.
"We have this nightmare scenario hovering in Asia," he said. "New, infectious diseases could hit anywhere on Earth. Last time it was Toronto, but it could have been San Francisco or any other city. It takes only one infectious person to spread it around."
Michael Lai, a molecular microbiology professor at the University of Southern California in Los Angeles, agrees.
"There is no question that there will be more and more new viruses in the future as we encroach upon wildlife habitat," said Lai. "The viruses we know today probably represent only a small fraction of the viruses existing in nature. We certainly have not seen the end of the story yet, and we need to learn to co-exist with these viruses."
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