Posted by: kenwbudd | March 14, 2010

H5N1 Avian Flu: Virulent Strain Developed in Labs

Engineered hybrids of H5N1 bird flu and H1N1 human flu strains have proven virulent in mice, raising the danger that a natural recombination would be deadly to humans.

For years, researchers have worried that H5N1 avian influenza would mix with human flu viruses, evolving into a form that keeps its current lethality but is far more contagious.

That hasn’t happened in the wild yet but the latest findings, published Feb. 22 in the Proceedings of the National Academy of Sciences, show how easily it can happen.

Mind the Gap
“Fortunately, the H5N1 viruses still lack the ability to transmit efficiently among humans.” However, the virus may soon be overcome this obstacle when it mixes with human flu strains. These are the findings of researchers led by University of Wisconsin virologist Yoshihiro Kawaoka. “The next pandemic is inevitable and it will be more devastating than the last.”

Current strains of H5N1 have infected 478 people since 2003, and killed 286 of them. It’s has difficulty transmitting to humans. It requires close contact and exposure to an infected person, bird or animal.

H5N1 in Birds

In birds, however, H5N1 is far more contagious, and here the virus has killed tens of millions of fowl. Fortunately, cases have been concentrated in Africa and Eurasia, but as the swine flu pandemic demonstrated, any flu contagious to humans will quickly spread on a global scale. This is mainly thanks to air travel and the free movement of peoples across state boundaries.

Influenza viruses mutate and swap genes easily, with co-infections turning animals into mobile petri dishes. In 2008, hoping to learn more about how H5N1 might evolve, researchers from the Centers for Disease Control and Prevention combined it with a common human flu strain.

The researchers engineered all 254 possible variants of hybridisation between the deadly H5N1 avian flu strain found in Borneo, and a, H1N1 human flu virus from Tokyo. They identified three strains that were both contagious and deadly, in mice.

The New Pandemic
A flu virus that kills mice won’t necessarily kill humans, but the results are very disturbing. All three killer hybrid strains possessed a protein taken from the human strain. Called PB2, the protein appeared to help the virus survive in the mice’s upper respiratory tract. As of now, bird flu stays in the lower respiratory tract, where it’s less likely to be casually transmitted.

Although the recent H1N1 pandemic has not proved to be as lethal as originally feared, it certainly exposed how unprepared the world is for new influenza strains. At the same time it also exposed the ability of pharmaceutical companies to frighten the WHO, governments and politicians into spending $Millions to stockpile ineffective vaccines.

Source of Infection
In May, Hong Kong University virologist Yi Guan, best known for finding the animal origin of SARS, was asked by Science Insider about the possibility of H5N1 and swine flu mixing.

“If that happens, I will retire immediately and lock myself in a sealed laboratory”, said Guan. “But, historically the Chinese mainland would be the most likely source of such a virus.”

Global Alert
Unfortunately, in such a situation, the imposed cover-up by local authorities would mean that the virus will have spread with a high rate of cross-infection and will have escaped globally, even before we are alerted to it’s existance. We will not be alerted until it has spread to the Western world and many people have become infected and died.

Lethal Viruses Escape
The other issue is the development of virulent and lethal strains in laboratories and institutions. There has been a sad history of viruses erroneously ‘escaping’ from pharmaceutical labs and there is no reason to believe that this will not happen in the future, despite due diligence.

Should we live our lives in a bubble? No, definitely not but we should be aware of the dangers we are facing and how these may manifest themselves. Yes, there is a lethal danger from a mutant virus but this danger is greater if the world’s health authorities are not communicating properly or collaborating on a global scale and this is something that can be mitigated against.


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