LAUREL, Md. -- Wild migratory birds may indeed play a role in the spread of bird flu, also known as highly pathogenic avian influenza H5N1.
A study by the U.S. Geological Survey, the United Nations Food and Agriculture Organization and the Chinese Academy of Sciences used satellites, outbreak data and genetics to uncover an unknown link in Tibet among wild birds, poultry and the movement of the often-deadly virus.
Researchers attached GPS satellite transmitters to 29 bar-headed geese a wild species that migrates across most of Asia and that died in the thousands in the 2005 bird flu outbreak in Qinghai Lake, China. GPS data showed that wild geese tagged at Qinghai Lake spend their winters in a region outside of Lhasa, the capitol of Tibet, near farms where H5N1 outbreaks have occurred in domestic geese and chickens.
This is the first evidence of a mechanism for transmission between domestic farms and wild birds, said Diann Prosser, a USGS biologist at the USGS Patuxent Wildlife Research Center. "Our research suggests initial outbreaks in poultry in winter, followed by outbreaks in wild birds in spring and in the breeding season. 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."
The part that wild birds play in the spread of bird flu has been hotly debated since the 2005 outbreaks in Qinghai Lake. Bird flu that spread beyond Asia and into Europe and Africa was later found to have genetically originated in the Qinghai Lake area. Discovering the Tibet connection adds another significant link in the global transmission of bird flu.
From 2003 through 2009, the Qinghai-Tibet Plateau experienced 16 confirmed outbreaks of the virus in wild and domestic birds, most of them in the newly documented migratory pathway of the wild bar-headed geese. "Every summer, more than 150,000 migratory birds use
|Contact: Diann Prosser|
United States Geological Survey