In recorded history, no disease has jumped the species barrier to infect humans, caused an epidemic and then never threatened us again--not without the discovery of a vaccine or cure to curtail the microbe. Some diseases, such as chicken pox, gradually become endemic to man and eventually result, if we are lucky, in nothing more than a mild childhood illness. Others, such as Ebola, retreat back to whatever animal reservoir they came from, stalking humanity from their hidden lair, only occasionally lashing out to bloody a village or crash a rural hospital. But diseases do not, as a rule, just go away.
In the past two weeks, with two new cases in China's Guangdong province and suspected cases turning up in Manila and Hong Kong, it seems that severe acute respiratory syndrome (SARS) is re-emerging too. The brutal culling of masked palm civets from Guangdong wildlife markets and farms that commenced last week has only exacerbated the sense that matters had been spiraling out of control. Forestry officials incinerated some civets, boiled others to death and drowned still more in disinfectant. Also called a civet cat, the small, furry mammal with big innocent-looking eyes is unrelated to real cats, being more of a first cousin to the mongoose. Nevertheless, it was as if China was sacrificing thousands of animals to ward off the Fourth Horseman of the Apocalypse.
The inside story of how that decision to cull civets came to be made, however, is one of aggressive public health, great courage and, most important, good science. It is very possible that research led by one virologist, Dr. Yi Guan, 42, and the extraordinary measures he took to make officials aware of his work may lead scientists to new ways to contain a fresh SARS outbreak.
Almost every week for the past year, Yi, a microbiology associate professor at the University of Hong Kong, has traveled by rail up to Shenzhen and Guangzhou to carry out fieldwork. It was Yi, along with the Shenzhen Centers for Disease Control, who in May took samples from Shenzhen's Dongmen Market and made the discovery that the masked palm civet, as well as the raccoon dog and hog badger, carried a virus remarkably similar to the SARS coronavirus. That research, initially hailed as a breakthrough in establishing the zoonotic origins of SARS, resulted in the Guangdong government temporarily banning the sale of civets. For Yi this should have been a crowning moment.
Instead, subsequent research by a mainland Chinese team challenged Yi's research, finding no evidence of the coronavirus in civets. Meanwhile, other scientists murmured that Yi's data was based on too narrow a range of samples drawn from just one market. Perhaps those civets, some argued, had been infected by humans in that market rather than the other way around. For Yi, a hot-tempered, chain-smoking workaholic, this was an unbearable impugning not just of his research but also of his genuine desire to apply his science to public health. Even more worrying was China's decision in August lifting the ban on sales of civets. By September, the markets were again crawling with them. One dealer in Shenzhen, when asked if he could procure a thousand civet cats, replied, "That's hard." He paused, then added, "It may take me a day to get that many."