-------- Original Message --------
6 May 2009
IDIN:
Pathobiologics
International: Biodefense Threat Analysis
& Communication Center
Subject: Pandemic Influenza:
Contingency Planning Discussion
Dear Colleagues:
The swine flu outbreak that began in Mexico and continues to spread
around the globe may be particularly dangerous for young, otherwise healthy
adults because it contains genetic components of the H5N1 avian influenza
virus, which can induce a "cytokine storm," in which a patient's hyper-activated
immune system causes potentially fatal damage to the lungs. -- Does New Swine Flu Virus Kill By Causing A 'Cytokine Storm'?:
ScienceDaily, 6 May 2009.
In the
context of Phylogenetic analysis and reassortment history of Human/Swine
H1N1 (tree.bio.ed.ac.uk) and specific H5N1 determinants in the lineage of
Novel A/H5N1, I would like to direct your attention to Human/Swine H1N1: Phylogenetics (all segments) with
additional swine isolates (Gavin Smith, Vijaykrishna Dhanasekaran, Justin
Bahl 02 May 2009):
PB1 gene – HKU 02 May 2009 (PDF)
Avian Gene Pool
-- AF144301 Goose/Guangdong/1/1996 (H5N1)
PA gene – HKU 02 May 2009 (PDF)
Avian Gene Pool
-- AF144302 Goose/Guangdong/1/1996 (H5N1)
M gene – HKU 02 May 2009 (PDF)
Eurasian avian gene pool
-- SCk/HK/SF189/2001 H5N1
-- AF144306 Gs/GD/1/1996 H5N1
-- Gs/GD/1/1996 H5N1
-- DQ997259 Sw/Guangxi/wz/2004 H5N1
Evolution of H5N1 into a human to human pandemic strain (Novel A/H1N1),
is now realized. The cytokine storm is the variable that makes the
present pandemic strain a serious concern.
Because proinflammatory cytokines are markedly elevated during H5N1
influenza virus infection, the “cytokine storm” is hypothesized to be the
main cause of mortality. Here, we demonstrate that mice deficient in the
hallmark inflammatory cytokines TNF-α, IL-6, or CC chemokine ligand 2 succumb
to infection with A/Vietnam/1203/04 (H5N1) virus, as do wild-type mice treated
with glucocorticoids for suppression of cytokines. Because cytokine inhibition
does not protect against death, therapies that target the virus rather than
cytokines may be preferable. -- Inhibition
of the cytokine response does not protect against lethal H5N1 influenza
infection: National Academy of Sciences, 5 June 2007.
Interactive Figure. Proposed Mechanism of the Cytokine
Storm Evoked by Influenzavirus. Supplement to: Osterholm MT. Preparing for the Next Pandemic. N Engl J Med 2005;352(18):1839-42.
Now as the virus continues to spread throughout the United States and
across the globe, we should be shortly gaining a grasp of the clinical
consequences of spread with a 1-7 day incubation period.
Related:
Looking forward to your feedback....
Stephen M. Apatow
Founder, Director of Research and Development
Pathobiologics
International
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