Bird imports may spread bird flu in Americas

Via Reuters, a thought-provoking report: Bird imports may spread bird flu in Americas—study. Excerpt:

Infected poultry imported by Brazil, Canada or Mexico is the most likely route for bird flu to spread into the Americas, a group of researchers predicted on Monday.

Migrating fowl would then spread the H5N1 avian flu virus throughout the region, the U.S. and British researchers predicted.

"We need to make sure that we are preparing developing countries in this hemisphere for this outbreak," said Peter Marra of the Smithsonian Institution and the National Zoo in Washington, who worked on the report.

Their study of the movement of H5N1 out of China and into the rest of Asia, across Europe and into parts of the Middle East and Africa shows that the poultry trade often started a spread that wild birds then took further.

"We conclude that the most effective strategy to prevent H5N1 from being introduced into the western hemisphere would be strict controls or a ban on the importation of poultry and wild birds into the Americas and stronger enforcement to curb illegal trade," they wrote in their report, published in the Proceedings of the National Academy of Sciences.

The story immediately reminded me of the Nigerian outbreak, which I'd read somewhere was due to an import of chicks from China. But this was apparently inaccurate:

"H5N1 outbreaks in South Korea, Russia, Mongolia, Nigeria, India, Pakistan, and Cameroon were inconsistent with both reported poultry trade (no poultry imports were reported from H5N1-infected countries) and the timing and direction of migratory bird travel in the month of the outbreaks," the researchers wrote.

Illegal trade in chicken feces for fertilizer and fish food, wild bird trade or other factors may have been responsible, they said.

The story tends to confirm the thesis of Andrew Nikiforuk in his book Pandemonium: that increasing world trade has introduced countless species into environments where they flourish at the expense of the native species. Free trade is all very well, but one has to draw the line this side of a pandemic.

Update: Here is Helen Branswell's report on the study, via Canada.com.