Tuesday, December 05, 2006
Research suggests bird flu could enter United States through South America
According to new research, the United States has been looking in the wrong place for bird flu.
A study in the latest Proceedings of the National Academy of Sciences found that birds flying north from Latin America are more likely to bring bird flu to the mainland United States than birds migrating from Asia.
Yet the United States’ $29 million bird flu surveillance program has focused heavily on birds flying from Asia to Alaska, where biologists this year collected tens of thousands of samples from wild birds nesting on frozen tundra before making their way south.
Those birds present a much lower risk than migratory birds flying from South America through Central America and Mexico, where controls on imported poultry are not as tough as in the United States and Canada, said A. Marm Kilpatrick, the study’s lead author.
“The risk is actually higher from the poultry trade to the Americas than from migratory birds,” said Kilpatrick, of the Consortium for Conservation Medicine in New York.
If bird flu arrives in Mexico or somewhere farther south, it could be a matter of time before a migratory bird carries the virus to the United States, Kilpatrick said.
Nations south of the United States import hundreds of thousands of chickens a year from countries where bird flu has turned up in migratory birds or poultry, he said.
“It’s not just a matter of worrying about who you trade with, but it’s a matter of thinking about who do your neighbors trade with, and who do your trading partners trade with,” Kilpatrick said. “We need to be looking both south and north.”
The study concluded that “current American surveillance plans that focus primarily on the Alaskan migratory bird pathway may fail to detect the introduction of H5N1 into the United States in time to prevent its spread into domestic poultry.”
U.S. officials cautioned that the study is not the final authority on the spread and prevention of bird flu.