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Tests Indicate Bird Flu Spread Largely from Infected Migratory Birds

On Monday, tests confirmed the 12 hens that died last week in the Russian city of Tambov were infected by the deadly H5N1 avian flu. Migratory birds seem to be spreading the disease around the world.

Recent outbreaks of H5N1 avian flu in Croatia, Romania and Turkey have confirmed what health officials had feared - that migratory birds are carrying the disease. As millions of birds migrate from the northern hemisphere to warmer southern climates, researchers are trying to stay one step ahead of avian flu by taking samples from the migratory birds.

Dr. Walter Boyce, is the director of the Wildlife Health Center at the University of California, Davis. He says the migrating birds in the Pacific flyway on the west coast of the United States often began their journey as far away as Siberia.

"Clearly bird flu is on the move. Our concern is wild birds as they migrate, might carry the bird flu with them. Our goal is to detect what viruses they are carrying and basically have an early warning that something might be getting ready to happen"

Researchers gather fecal and throat samples from the birds, then inject them into developing eggs. If the embryo dies, the scientists test to determine what virus caused the death. The results will help researchers develop a vaccine for avian flu, if, as is feared, a mutated strain of the disease begins to spread from human to human.

At the University of Rochester Medical Center in New York State, an experimental vaccine is now being tested in clinical trials. Dr. John Treanor explains. "People have never been exposed to bird flu before, and so you need to give the immune system a greater stimulus to make it work. We have seen antibody response. Those are those germ-fighting proteins in the blood in people who have received the vaccine, and we think that would mean they would be protected against bird flu."

Final results of the vaccine trial should be available in November.

Since emerging in 2003 in South Korea, H5N1 has killed more than 60 people in four Asian countries, primarily from contact with live poultry or wild birds.

Michael DiGirolamo is the director of airport operations at Los Angeles International Airport, the major hub for airline passengers entering the U.S. from Asia. He says the airport is preparing in case a sick traveler is infected with avian flu and health officials quarantine the plane.

"This means that the airport will have to provide a facility for the CDC and U.S. Customs and Border Protection that will be able to quarantine as many as 400 people for 48 hours."

As the avian flu migrates, world health officials are meeting in Canada this week for talks on preventing a further spread of bird flu.