WASHINGTON — Officials from the U.S. Department of Agriculture don’t think wild birds infected with the deadly H5N1 avian influenza virus will enter the United States from overseas through either of the two major North American migration routes, the Pacific and Atlantic flyways.
"The distance may be too long for a (sick) bird to get that far," said Steve Kappes, deputy administration of the U.S.D.A.’s Agricultural Research Service, at a press briefing.
Mr. Kappes supported his comment with data from a seven-year study of more than 8,200 wild bird samples taken in Alaska, where Asian and North American birds mingle in the summer. Virtually all of the A.I.-infected birds found in the study originated in North America rather than Asia, where H5N1-caused A.I. has been a serious issue, particularly in Southeast Asia. The virus also has been found in birds in Africa and Eastern Europe.
To date, highly-pathogenic H5N1 A.I. has been the cause of death, either by sickness or culling, of approximately 200 million birds since 2003. The virus also has killed 168 people, according to the World Health Organization.
Secretary of Agriculture Mike Johanns called the risk of H5N1 in the U.S. "relatively low." Earlier this month Mr. Johanns met with Jacques Diouf, the director-general of the Food and Agriculture Organization of the United Nations, and the two officials signed an agreement to increase coordination on several farm and livestock issues, including A.I.
This past month, H5N1 infected a large commercial turkey farm in the United Kingdom. That outbreak, Richard Lobb, spokesperson for the National Chicken Council, said "serves as a reminder we’re not out of the woods yet; this isn’t strictly an Asian problem. The key will be to keep it out of any more commercial flocks."
At this week’s briefing, Rick Kearny of the U.S. Department of the Interior’s U.S. Geologic Survey said the U.S.G.S. will increase A.I. testing this year.
"We do know based upon results in Europe and Asia that the first sign of highly pathogenic H5N1 is often-times the observation of sick and dying wild birds, so we’ll be looking at that more closely," he noted. The agency will expand its surveillance of wild-bird populations to the Central migratory flyway, which extends from North Dakota south through Texas. Last year, the U.S.D.A. and the Department of the Interior together made more than 100,000 tests for A.I. on wild birds. While H5N1 was not found, the testing program did detect a strain of low-pathogenic bird flu in six states, including Delaware, Illinois, Maryland, Michigan, Montana and Pennsylvania.
Mr. Johanns assured consumers U.S. poultry is safe, even if the deadly virus is found here.
"If there is a detection of high-path H5N1 in this country, it should not cause a loss of confidence in the safety of poultry," he said.