Chances are your shirt, your pants and your underwear all came from southern China, the new manufacturing center of the world. Add one more export: your flu virus. With its dense populations of people and animals trading germs back and forth, southern China has been the traditional birthplace of influenza, including the nasty strain of H5N1 bird flu that's keeping public-health officials awake at night. The viruses that evolve in a chicken in southern China's Guangdong province could eventually end up in your lungs--and that's what makes a chain-smoking, impetuous Chinese virologist named Dr. Guan Yi so important.
Guan, 43, who was born in mainland China but is chiefly based at the University of Hong Kong, is a human early-warning system in the shifting viral landscape of southern China and now southeast Asia, where bird flu has been endemic since the end of 2003. Although Beijing is traditionally secretive about disease within its borders, Guan's network of mainland Chinese contacts and his secondary position at Shantou University in Guangdong province have helped his team gather biological samples from more than 100,000 birds in the region over the past five years, more than any other scientist. It's hard, dirty work--every day researchers pick through less than hygienic live poultry markets, persuading traders to allow them to take blood and feces samples from their chickens and waterfowl. From those samples, Guan and his team have managed to sequence the genetic code for more than 250 strains of H5N1--giving them a chillingly accurate picture of how widespread bird flu is in the region and how the virus is mutating. "We have to know what's in animals, so we know what could be in human beings," says Guan.
He knows from experience how important that is. It was Guan who discovered, through field data he gathered, that civet cats were probably spreading the SARS virus to human beings. Guan formulated his hypothesis just as SARS was beginning to return in Guangdong at the start of 2004. A more patient scientist might have waited and harvested more data. But patience is not Guan's strong suit, and with new human cases surfacing, there wasn't time. Putting his scientific reputation on the line, he gave his preliminary results to authorities in Guangdong and urged them to cull civets being sold in wild-animal markets. After some hesitation, they did--and since then, the only new SARS cases have come from a handful of lab accidents. "My personal effort stopped the second SARS outbreak," Guan says. "And hopefully my personal effort will contribute to saving the world from this pandemic."
Guan doesn't lack for scientific chutzpah, but it takes a little self-confidence to rise from Jiangxi Medical College in the heartland of China, where Guan earned his M.D. at age 21, to a corner office in Hong Kong and a position as one of the most important influenza experts in the world. As we inch closer to a possible flu pandemic, Guan keeps gathering his data, doing his part to piece together the puzzle that is the avian flu. "I do this work for the whole world," he says. "For the first time, human beings have the ability to prevent a pandemic. How many lives will we save?" And how much time do we have left?