US : Who to blame for flu? Maybe the U.S., study finds

Via Reuters :

" The United States may provide an incubating ground for some flu strains, helping them migrate to warmer climates, U.S. researchers said on Thursday.

For many years, researchers assumed that flu strains were mostly the product of China and Southeast Asia.

But a team at the University of Michigan, the Howard Hughes Medical Institute and Florida State University found that not all strains of flu circulating in North America die off at the end of influenza season.

Some of those appear to head to South America, and some migrate even farther, the reported. That may have happened with the H1N1 swine flu pandemic, they added.

"We found that although China and Southeast Asia play the largest role in the influenza A migration network, temperate regions -- particularly the USA -- also make important contributions," said Trevor Bedford of the University of Michigan, whose study appears in the Public Library of Science journal PLoS Pathogens."