2006年VOA标准英语-US Testing for Bird Flu in Alaska(在线收听

By Brian Padden
Alaska
30 June 2006
 
Watch Avian Report

They face no passport controls or border police. They come unchecked by the thousands, and because they do, authorities in the United States fear they could be a potentially lethal threat. They are migratory birds that wing their way from Asia to the Americas, the feared source of a possible continental pandemic. So far there have been no confirmed cases of the deadly H5N1 strain of avian flu in North America and U.S. health officials want to keep it that way. In a new effort to prevent the disease from reaching America's shores, the U.S. government has started testing wild birds in Alaska. VOA's Brian Padden was there and has this exclusive broadcast report.

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Chris Nicoli 
  
The Yukon Delta National Wildlife Refuge is a remote and desolate region of the Alaskan tundra. It is here that wild birds from both Asia and America come to feed and nest during the summer months. Scientists fear these nesting grounds might just be the gateway through which a deadly strain of avian flu enters the Americas.  

So it is here that biologists such as Chris Nicoli have been dispatched to catch and test birds for avian flu.  He is participating in a U.S. government-sponsored early warning detection program that will test more than 15,000 birds in Alaska this summer. 


Brant Goose
  
  
The Brant Goose is one of the prime suspects being targeted for testing. An area near the Tutakote River is a nesting ground for Brant Geese and Eider ducks, two of the 27 species being tested throughout the state.  

Bob Leddy is coordinating the avian flu early warning surveillance program for the U.S. Fish and Wildlife Service in Alaska.

"The virus itself is often passed through water and where birds mingle in water," Leddy said. "The species we're looking for here in the Tutakote field camp are primarily Brant, Common Eider and Spectacle Eider. These birds were chosen because they have regular known contact with Asia and may bring the disease back here."  

The biologists test mostly mother birds because they are easier to catch. They either use snap traps placed over a nest of eggs, then wait for the mother bird to return. Or they try to sneak up on a nesting bird using a hand net.

 
Jim Sedinger 
  
Biologist Jim Sedinger with the University of Nevada at Reno has been studying birds in Alaska for more than 20 years. He says what scientists already know about migratory patterns can help them identify and contain a possible outbreak.

"These Brant here mostly go to California and Mexico," he said. "If we found a positive Brant for example, you wouldn't immediately be concerned about poultry in Nebraska."  

So far, no avian flu has been found in the wild birds tested in Alaska. In fact, some in the scientific community say the threat of wild birds spreading the disease has been overstated. Still, Bob Leddy says developing this surveillance network has been critical.

 
Bob Leddy
  
"We know very little about the transmission of avian influenza among populations of birds and then certainly from birds to humans.  We will have many, many samples," Leddy said. "We will ultimately be testing for all strains of avian influenza and we'll have a much better understanding of its prevalence in different species, we'll start to learn about transmission."   

The more biologists learn about transmission, the more effectively this new type of border guard can protect a concerned public from H5N1, the deadly strain of avian flu

  原文地址:http://www.tingroom.com/voastandard/2006/6/33768.html