Friday, January 27, 2006

Learning the deadly details

The Vancouver (Canada) Sun reports today on a couple of scientific discoveries about the current strains of bird flu making the rounds in Europe and Asia. The first announcement is that the European strain (the one centered in Turkey) is remarkably like the 1918 flu that killed millions. The second discovery is even more sinister: seems the new bird flu has some special genetic adaptations that allows it to commandeer human cells at a critical level.

Researchers from St. Jude Children's Research Hospital in Memphis, Tenn., have found that bird flu viruses carry a gene that can latch onto many crucial proteins inside human cells, presumably disrupting their function and causing far more severe disease than human viruses.

The research provides a new hypothesis for why certain bird flu viruses are particularly lethal for humans.

Mapping the gene structures of over 2196 bird influenzas, researchers discovered that bird viruses produce a gene that is particularly ugly in human cells.

In bird viruses, the gene produces a protein that allows the virus to bind to "scaffolding" proteins inside human cells.

"It's like a large number of policemen being held hostage. Society falls apart," says McGeer.

In human viruses, the protein doesn't bind to certain cells, which may explain why they're not as virulent.

It hasn't been proven yet. "But, we think that if you interfere with that many proteins in cells, you're going to have a deleterious consequences," said author Dr. Clayton Naeve of St. Jude.

The finding fits with what doctors on the ground in Asia have seen: The H5N1 virus can attack not just the airways, like regular flu, but multiple organs and systems, including the kidney, liver, spleen and brain. Infection has been fatal in more than half the reported cases, and most cases occur in previously healthy children and young adults.

The H5N1 avian flu sweeping across Asia has this "bird" form of the protein. The milder pandemics of 1957 and 1968 had the "human" one.


"Does it tell you H5N1 is going to be the next pandemic? No. What it does is add to our understanding of the evolution of influenza viruses."

Naeve says it is possible that whatever makes H5N1 so pathogenic, or toxic to humans, could persist even if the virus adapts to spread easily from humans to humans, and becomes pandemic.

The still hard-to-catch bird flu at present is lethal when it does cross over.
The virus has infected 152 people in six countries since 2003, killing 84 of them.
Canadian officials are already implementing public health strategies to get people to wash their hands frequently, sneeze into tissues, and to cover their mouths.

Here at Oklahomily CNC we are implementing a new "wash the car frequently and watch where you put your hands" policy because of the devil birds' penchant for dropping toxic waste on the motor pool. You never know, those birds could be cavorting with sick migratory fowls. This is Level 2 (orange). Level 3 (red) would require us to clean out the garage and start parking inside. Given our lack of motivation, it is hard to say what would trigger a Level 3 alert.

But at least we have a plan.


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