- "Influenza has been touted as a bioweapon, and the
news about H5N1 could be used to produce a more deadly strain. It's always
a possibility, says Webster, but 'flu is not the most obvious or easiest
candidate for malicious use."
-
- Hello, Jeff - When do you think the above was written?
-
- AUGUST 24, 2002
-
- That is BEFORE the so-called jump in virulence.
-
- The article aslo compares the strain H5N1 as similar
to H1N1 the Spanish Flu of 1918. It sounds to me like they have been researching
this strain long before we even heard of bird flu jumping species barrier.
Interesting.
-
- Patty
-
-
- Deadly Flu Evades Bodies Defences
- Virus Treats The Immune System Like 'Duck Soup'
-
- By John Whitfield
- Nature.com
- August 26, 2002
-
- The lethal Hong Kong influenza is invisible to our body's
immune defences, new research shows. The finding could help to identify
future dangerous 'flu strains and perhaps explain why 'flu outbreaks of
the past were so deadly1.
-
- The strain in question, called H5N1, is immune to molecules
called cytokines - the first line of defence against 'flu.
-
- In 1997, H5N1 jumped from chickens to humans in Hong
Kong. Eighteen people were hospitalized, six of whom died. Three million
chickens were slaughtered to contain the virus, which can spread from birds
to humans, but not between people.
-
- "After infection with 'flu, cells start churning
out cytokines," says virologist Robert Webster of St Jude Children's
Research Hospital in Memphis, Tennessee. This triggers an immune response
in uninfected cells, and suppresses most strains.
-
- But to Hong Kong 'flu, cytokines "might as well
be duck soup", says Webster - "it totally ignores them".
-
- Simple but deadly
-
- Just one genetic mutation lets H5N1 evade cytokines,
Webster's team found. The researchers put the crucial gene into another
form of 'flu; infected pigs became much sicker than those given the unmodified
virus. The animals also remained infectious for longer.
-
- Now the gene has been identified, it could be used to
track down other threatening 'flu strains, says Albert Osterhaus, who studies
'flu at Erasmus University in Rotterdam, the Netherlands.
-
- Quite how H5N1 sidesteps the immune system escape is
not known. It may have other nasty tricks besides the changed gene, says
Osterhaus. The effects of 'flu depend on the way that its eight genes interact,
and that differs depending on the species it infects.
-
- Back with a vengeance?
-
- Hong Kong 'flu is similar to the strain that killed more
than 20 million people in the 1918 'flu pandemic, Webster says. Both, for
example, killed people in their mid-30s, who should have robust immune
systems. They might share the immune-dodging ability, he thinks.
-
- But there are also differences between the strains, says
Alan Hay, a 'flu researcher at the National Institute for Medical Research
in London. "It's a novel and very interesting finding," he says,
but "it doesn't tell us anything" about the 1918 pandemic.
-
- Influenza has been touted as a bioweapon, and the news
about H5N1 could be used to produce a more deadly strain. It's always a
possibility, says Webster, but 'flu is not the most obvious or easiest
candidate for malicious use.
-
- The threat we already face from the disease means that
the benefits of the research outweigh the risk of new knowledge, Webster
says. "We have to have this information. Sooner or later we're going
to get a bad one, and by understanding the beast we've got a better chance
of killing it."
-
-
- References
- Seo, S. H., Hoffman, E. 7 Webster, R. G. Lethal H5N1
influenza viruses escape host anti-viral cytokine responses. Nature Medicine,
Published online, doi:10.1038/nm757 (2002). |Article|
-
- © Nature News Service / Macmillan Magazines Ltd
2003
- http://www.nature.com/nsu/020819/020819-14.html
-
- 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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