Look south for bird flu

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Study: Look south for bird flu

WASHINGTON (AP) -- Birds from Latin America -- not from the north --

are most likely to bring deadly bird flu to continental United States,

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.

Bird trade an issue

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, 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 sonian 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 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. "

The report is the first to combine the DNA fingerprint of the H5N1

virus in different countries with data on the movement of migratory

birds and commercial poultry in those countries.

The analysis helped to determine, for example, that the outbreak of

bird flu in Turkey likely didn't come from poultry imports from

Thailand, as previously thought. Instead, the probable source was

migratory birds in Russia, where the virus had similar DNA to the

virus in Turkey.

The study found that:

• Bird flu was spread through Asia by the poultry trade.

• Most of the spread throughout Europe was from migratory birds.

• Bird flu spread into Africa from migratory birds as well as poultry

trade.

U.S. officials cautioned that the study is not the final authority on

the spread and prevention of bird flu.

" When you look at scientific literature, it's a big puzzle. This puts

in a few more pieces, " said Swayne, director of the Agriculture

Department's Southeast Poultry Research Laboratory in Athens, Ga.

Swayne cautioned that researchers looked only at countries' import

restrictions through 2005.

" I'm not saying it's the fault of the study; the study is designed to

look at what happened in the past, " Swayne said. " We have to be very

careful not to over-interpret. There is a limit on how recent the data

is. "

In addition, Agriculture Department officials said they are not

focusing exclusively on Alaska.

More resources have been spent in Alaska than in other states so far,

but testing is happening throughout the lower 48, and the U.S. is even

helping Mexico do surveillance, said Tom DeLiberto, the department's

National Wildlife Disease Coordinator.

" We have more information now than we did when we designed the

surveillance effort last fall, " DeLiberto said.

" We knew that we had limited information and couldn't design a system

that looked at just Alaska, " he said. " You have to build a robust

system that could cover a lot of different potential pathways. We know

as we get more information, we'll adapt our system. "

Since the deadly H5N1 virus emerged in Hong Kong in 1996, at least 154

people have died and hundreds of millions of chickens, ducks, geese

and turkeys have died or been killed to keep it from spreading.

So far, the virus has killed mostly people who had close contact with

sick birds or their droppings, but scientists fear the virus could

someday mutate into a form that spreads easily among people.

http://www.cnn.com/2006/HEALTH/12/04/bird.flu.ap/index.html