Posted on 08/28/2006 7:20:10 PM PDT by blam
More tests confirm low-path bird flu in Michigan
Mon Aug 28, 2006 6:31pm ET
U.S. News
WASHINGTON (Reuters) - A second round of tests on swans in Michigan confirmed the birds have a low-pathogenic strain of H5N1 and not the deadly avian influenza virus that has killed more than 141 people in Asia, Europe and Africa, the U.S. Agriculture Department said on Monday.
Routine tests conducted in a Michigan gaming area earlier this month found two of about 20 swans had what was believed to be a low-pathogenic strain of H5N1.
"Genetic testing confirms that these swans were not carrying the highly pathogenic strain of H5N1 avian influenza that is circulating overseas," USDA said in a statement.
The swans had shown no sign of sickness, which indicated this was low pathogenicity avian influenza. Pathogenicity refers to the ability of the virus to produce a disease.
A low-pathogenic strain, which produces less disease and mortality in birds than does a high-pathogenic version, poses no threat to human health.
The low-pathogenic strain of H5N1 has been found six other times in the United States since 1975, most recently in 2002. It is common for mild and low pathogenic strains of bird flu to appear in the United States and other countries.
The infected swans were found as part of an increased surveillance program put in place after USDA received $91 million in supplemental funding from Congress for bird flu last December.
The H5N1 bird flu strain, which has killed an estimated 141 people and forced hundreds of millions of birds to be destroyed, has not been found in the United States.
Ping.
Thanks for the post.
L
8/28/2006, 7:33 p.m. ET
The Associated Press
WASHINGTON (AP) — Bird flu detected in a Michigan swan was the less dangerous, low-pathogenic version of the virus, government officials confirmed Monday. How pathogenic a virus is refers to its ability to cause disease.
High-pathogenic H5N1 virus has devastated poultry in several countries. The government has increased monitoring in an effort to find the disease if it arrives in the United States.
The so-called "high-path" or Asian version of the flu spreads rapidly and is often fatal to chickens and turkeys. It also has infected people, mostly through direct contact with infected birds.
The Michigan swan had a low-pathogenic virus, sometimes called "North American" H5N1, that is thought to commonly occur in wild birds. It usually causes minor symptoms or no symptoms at all.
Tests found bird flu in two mute swans in Michigan, and earlier genetic testing ruled out more virulent Asian flu. One of the samples had high enough levels of flu to allow confirmatory testing, which found the virus was a low-pathogenic flu.
H5N1 refers to a combination of two groups of proteins: the hemagglutinin, or H, proteins, of which there are 16, and neuraminidase, or N, proteins, of which there are 9.
The same combination, such as H5N1, can come in either high-path or low-path forms.
H5N1 seems specific. Shouldn't they be classified as (a) and (b)?
Beats me. I learn something new about this 'stuff' every day.
ping
Bump
It is wise that they are vigilant and are testing. Was the virulent strain supposed to get here, and where was it supposed to first appear?
I've seen September as the estimated time of arrival in Alaska, I believe.
Thanks....I'm sure they are up there checking things out!
I wonder if the low path strain conveys immunity to the high path strain?
I'm thinking of the way cowpox protected from small pox...
I've wondered the same myself. Maybe one year get the H5 and the next year get the N1.
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