- Excerpt from Henry Niman's commentary: "In addition,
all of the isolates have the PB2 polymorphism E627K. This polymorphism
is of concern because previously it was almost exclusively found in human
flu such as H1N1, H3N2, and H1N2. "
-
- Sounds omnious - especially with polymorphisms found
in human viruses like H1N1 Spanish Flu. I had a feeling that the H5 would
combine with H1N1 and have been speaking about it for a couple of years.
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- Patty
-
- European Swine Signatures In H5N1 Bird Flu
At Qinghai Lake
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- By Dr. Henry L. Niman, PhD
- Recombinomics Commentary
- 7-20-5
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- The sequences from the Qinghai Lake H5N1 bird flu isolates
have just been made public at GenBank. There are 20 H5N1 isolates from
2005 which include 12 isolates from Qinghai Lake. The 12 sequences for
the M2 gene show wiid type sequences in the ion channel, indicating the
H5N1 in the tested waterfowl are Amantadine sensitive.
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- These isolates have gained attention because the deaths
of the water fowl by H5N1 is without precedent and Qinhai Lake is at the
intersection of the two major migratory bird fly ways in Asia. H5N1 at
Qinghai Lake could be dispersed throughout Asia and into Europe and North
America by migratory birds that use these two flyways.
-
- In addition, all of the isolates have the PB2 polymorphism
E627K. This polymorphism is of concern because previously it was almost
exclusively found in human flu such as H1N1, H3N2, and H1N2. All published
human sequences since 1933 have E627K. This polymorphism was rarely found
in sero-types associated with birds, like H5N1, The only reported H5N1
isolates prior to the isolates at Qinghai that had the human polymorphism
were two isolates from mouse brain, including one from the duck meat imported
into Japan from Shandong, and human or wild cat isolates from the outbreaks
in 1997 and 2004.
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- The H5N1 at Qinghai kills experimental chickens within
20 hours and experimental mice in 3-4 days. There are also third party
reports of human fatalities in Qinghai. The concerns have been heightened
because the birds will soon migrate away from Qinghai Lake and into Europe,
eastern Asia, and the Indian subcontinent.
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- An initial analysis of the PB2 sequence reveals small
clusters of polymorphisms not normally found in H5N1 sequences at Genbank.
One cluster matches the polymorphisms found in the PB2 gene of a 1999
isolate from a child in Hong Kong. The isolate was unusual because it
was closely related to European swine isolates, but there was no linkage
between the Hong Kong child and Europe so the source of the H3N2 virus
was unknown. The PB2 genes from the water fowl at Qinghai Lake have additional
polymorphisms found in H1N1 swine isolates from Europe.
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- The mammalian signatures, like the human signature, which
is also found in many swine isolates, are indicators of an expanding host
range. Moreover, the European connection suggests that migratory birds
do move sequences from Europe to Hong Kong via flyway intersections such
as Qinghai Lake, where birds from Asia's eastern and north central flyway
can give rise to dual infections, leading to novel recombinants.
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-
- Patricia A. Doyle, PhD
- Please visit my "Emerging Diseases" message
board at: http://www.clickitnews.com/ubbthreads/postlist.php?
Cat=&Board=emergingdiseases
- Zhan le Devlesa tai sastimasa
- Go with God and in Good Health
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