Desolate but beautiful, tucked in a northwestern corner of China so distant from populated areas that it lies near the spot where Beijing developed its first atomic bomb, Bird Island could be the last place on earth. But for migratory birds, the island actually a small peninsula protruding into Qinghai Lake, China's largest saltwater lake is the avian equivalent of a busy international airport. Each year in the late spring and summer, hundreds of thousands of wild birds of almost 200 different species land here to lay eggs and hatch their young, before departing for wintering grounds that range from Europe to southern Asia. On May 4, Li Yinghua, a ranger at the Qinghai Nature Reserve's Bird Island Station, was making his daily rounds near an area popular with bar-headed geese when he spotted something he'd never seen in his two decades at the reserve. "One of the geese had wandered away from the group," he recalls. "It was walking so strangely, wobbling from side to side as if it were drunk." His voice drops to a whisper. "This goose seemed to be shivering." Li called his superiors who took the animal away for tests. He heard that it died soon after.
Over the next six weeks, thousands of other birds, chiefly bar-headed geese, would perish in the same way. In Hong Kong, animal virologist Dr. Guan Yi heard about Qinghai and immediately guessed that he knew the cause: h5n1, a deadly avian-flu virus that has ravaged Southeast Asia's poultry flocks and infected over 100 people since the end of 2003. Although the Chinese government initially rebuffed requests by the Geneva-based World Health Organization (who) to visit the site of the Qinghai outbreak it wouldn't be given clearance until the end of June Guan circumvented the red tape, using his network of mainland contacts to gather nearly 100 samples from dead birds. The results, which he and his team published on July 7 in the journal Nature, confirmed his suspicion: wild birds, generally thought to be immune to the effects of h5n1, were succumbing to the virus. That was important news. If h5n1 became established among migratory species, it would raise the risk that the virus could be spread across oceans and continents. Understanding just how the viral transmission belt operates "is urgent work for the entire world," Guan told Time recently, speaking in his office at the University of Hong Kong (H.K.U.). "The virus could go to Europe, and from there to India. These questions are critical not just for science, but for humankind."
If that sounds like an alarmist's hype, it's not. For some time, health experts have warned of a worldwide bird-flu pandemic that could kill millions of people and wreck the global economy. "The most serious known health threat facing the world is avian flu," said who director general Dr. Lee Jong-wook earlier this year. And the threat is growing all the time, as nature keeps dropping hints that the links in a chain of events leading to a deadly pandemic continue to be forged. This summer, h5n1 spread west perhaps in migrating birds to new territory, including Mongolia, Tibet, Siberia
and Kazakhstan. European countries are taking precautions by tightening surveillance of flocks within their borders. Last week, the Romanian government said it found several cases of avian flu in domestic birds; last month, E.U. medical and veterinary experts told member states to "intensify" the work to update their avian influenza contingency plans.
Meanwhile, in Southeast Asia, where at least 60 people have died and 150 million poultry have perished or been culled because of avian flu since the end of 2003, the virus is still active. A Jakarta woman died of the disease on Sept. 26, the third confirmed fatality from bird flu in Indonesia. Several other deaths are being investigated for bird flu and a number of other sick patients are being tested for the disease. The Indonesian government has declared a national "extraordinary event." The h5n1 virus has already shown it can be deadly to people who come into direct contact with infected birds or eat uncooked poultry. But bird-to-human transmission is relatively controllable because diseased flocks can be isolated or, usually, eliminated. The sum of all fears is that h5n1 could mutate into a strain with the ability to jump easily from person to person, as ordinary flu does. That could trigger a once-in-a-century catastrophe.
How many would lose their lives? The who estimates that in a best-case scenario, between 2 million and 7.4 million people would die worldwide, but the death toll could be considerably higher if the next pandemic virus turns out to be more virulent. In the great flu pandemic at the end of World War I, up to 100 million lost their lives, and there's unnerving evidence that h5n1 has the potential to be just as deadly. Two landmark studies published last week by U.S. scientists showed that, unlike most other new flus, the 1918 virus jumped directly from birds to humans just as h5n1 has. In a joint statement following the release of the research, Dr. Anthony S. Fauci of the National Institute of Allergy and Infectious Diseases and Dr. Julie L. Gerberding of the U.S. Centers for Disease Control and Prevention (cdc) warned: "Should the avian virus develop the ability to spread easily among people, a worldwide influenza pandemic could ensue, potentially rivaling in impact the 1918-19 pandemic."