Earlier this year, bird flu panic was in full swing: The French feared for their foie gras, the Swiss locked their chickens indoors, and Americans enlisted prison inmates in Alaska to help spot infected wild birds.The H5N1 virus - previously confined to Southeast Asia - was striking birds in places as diverse as Germany, Egypt, and Nigeria, and a flu pandemic seemed inevitable.
Then the virus went quiet. Except for a steady stream of human cases in Indonesia, the current flu epicenter, the past year's worries about a catastrophic global outbreak largely disappeared.
What happened?
Part of the explanation may be seasonal. Bird flu tends to be most active in the colder months, as the virus survives longer at low temperatures. 'Many of us are holding our breath to see what happens in the winter,' said Dr. Malik Peiris, a microbiology professor at Hong Kong University. 'H5N1 spread very rapidly last year,' Peiris said. 'So the question is, was that a one-off incident?'