Scientists Criticize Bird Flu Search

Birds from Latin America — not from the north — are most likely to bring deadly bird flu to the main U.S., researchers said Monday, suggesting the government might miss the H5N1 virus because biologists have been looking in the wrong direction.

The United States' $29 million bird flu surveillance program has focused heavily on migratory birds flying from Asia to Alaska, where researchers 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 that make their way north from South America through Central America and Mexico, where controls on imported poultry are not as tough as in the U.S. and Canada, according to findings in the latest Proceedings of the National Academy of Sciences.

Nations south of the U.S. import hundreds of thousands of chickens a year from countries where bird flu has turned up in migratory birds or poultry, said A. Marm Kilpatrick, lead author of the study.

"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. Other researchers on the study came from the Smithsonian Institution.

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.

"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...

Bird imports may spread bird flu in Americas-study

04 Dec 2006 22:00:10 GMT
More By Maggie Fox, Health and Science Editor

WASHINGTON, Dec 4 (Reuters) - 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.

Marra said Canada, Mexico and other countries all regularly import day-old chicks from other regions. The United States does not.

The H5N1 avian flu virus has killed or caused the slaughter of more than 200 million birds globally since 2003. While it mainly infects birds now, experts say it could evolve into a pandemic strain that infects people easily, although up to now it has infected only 258 people and killed 154.

Both poultry imports and migrating birds have been blamed for the virus' rapid spread. It has now been found in birds in 55 countries, and neither repeated slaughtering of flocks nor vaccination has been able to stop it completely.

U.S. government teams are monitoring waterfowl flying into Alaska from Siberia and then south from Alaska, and they are also checking birds along the northern U.S. border for the virus.

GENETIC CLUES

Marra, Marm Kilpatrick of the Consortium for Conservation Medicine in New York and colleagues looked to see how and where H5N1 has spread in the past. This can be done by looking at the genetic sequence of the virus, which is constantly mutating, and at migratory patterns.

While the virus mostly spread in Asia through the poultry trade, almost all of the spread throughout Europe was due to migratory birds and both poultry and wild birds carried it into and across Africa, they concluded.

Some outbreaks are more difficult to explain.

"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 genetic fingerprints of the viruses found in these countries gave little clue as to their origin, Marra said.

They said their study showed it is unlikely bird flu will come into the United States and Canada via Siberia.

Marra said the surveys of live birds in Alaska and on the west coast should continue. "Yet to not have some sort of systematic surveillance around the rest of the United States is, I think, a mistake," Marra said in a telephone interview.

I hate the word "ban" but considering that a small outbreak of less deadly strains of AF immediately cause bans of US poultry by other countries, I would have no problem with a halt to all poultry imports to the US if it were a means to an end of this particular strain.

But that is legal trade, the illegal trade is an entirely different kettle of fish. I read earlier today about the millions of pounds of illegal poultry, meat, fish and other "edibles" that have been confiscated/destroyed this year just in NYC alone.

And she types this as she thinks of the 170,000 broiler/fryers being grown for Perdue that are her nearest neighbors................

It wouldn't mean an 'end' to the virus, but it might seriously reduce the risk to us here in the States.

You're right, although the less places it has to go the quicker it may just die out. But your point is well taken.

Or sack of hens as it were.

Yeah, sort of a mixed metaphor on my part :)

I'd worry less about Purdue, who would shut down in an instant to save their corporate skins, than I would about smuggled wild birds.

I've lived in poultry country long enough to know exactly what the producers (Perdue is not the only one in this area) do in cases of AF outbreaks, and I know it is more for corporate than for the general public, but in this type scenario it works for both - so who cares :)

I have no doubt about the illegal trade (your smuggled wild birds) that is where the danger lies both to the general public as well as the domestic poultry industry. One idiot who smuggles in an infected bird and then gets near a domestic chicken house.......and well, we're in trouble.

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