Scientists from the U.S. Geological Survey, the U.N. Food and Agriculture Organization and the Chinese Academy of Sciences used satellites, outbreak data and genetics to discover a link in Tibet among wild birds, domestic poultry and the movement of the often deadly virus, a USGS release reported Thursday.
Researchers attached GPS transmitters to bar-headed geese, a wild species that migrates across most of Asia and that died in the thousands in an outbreak of bird flu in Qinghai Lake, China, in 2005.
GPS tracking data showed wild geese tagged at Qinghai Lake spend their winters in a region outside Lhasa, the capital of Tibet, near farms where H5N1 outbreaks have occurred in domestic geese and chickens.
"Our research suggests initial outbreaks in poultry in winter, followed by outbreaks in wild birds in spring and in the breeding season," Diann Prosser, a USGS biologist, said.
"The telemetry data also show that during winter, wild geese use agricultural fields and wetlands near captive bar-headed geese and chicken farms where outbreaks have occurred."
Bird flu outbreaks that spread beyond Asia and into Europe and Africa were later found to have genetically originated in the Qinghai Lake area, and finding the Tibet link adds another significant clue to the global transmission of bird flu, the researchers said.
Since 2003, H5N1 has killed 300 people and has led to the culling of more than 250 million domestic poultry throughout Eurasia and Africa.