Here’s a new story
Eastern European avian flu similar to 1918 strain View Larger Image Vietnamese vendors prepare meat for New Year’s shoppers at a downtown Hanoi market on Thursday. Chicken or duck is often central to Lunar New Year feasts. Photograph by : Richard Vogel, Associated Press Article Tools Printer friendly E-mail Font: * * * * Sharon Kirkey, CanWest News Service Published: Friday, January 27, 2006 More similarities have been found between the bird flu creeping into Eastern Europe and the 1918 Spanish flu that decimated populations worldwide, including the discovery of an entirely new way bird flu may kill human cells.
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.
Published in today’s issue of the journal Science, the research comes as Canada prepares to release an updated pandemic flu plan that includes new infection control and border measures, from strategies to get people to wash their hands and cough into Kleenex, to surveillance systems in airports and emergency rooms to detect the virus’s introduction into Canada.
There’s no evidence so far that the H5N1 avian flu is transforming into the next human pandemic flu strain, but “we certainly are really increasing our efforts in terms of preparedness,” says Dr. Theresa Tam, of the Public Health Agency of Canada.
But a SARS survivor, and infectious disease specialist, says Canada is “nowhere close” to being ready for a pandemic should it happen. Dr. Allison McGeer, of Mount Sinai Hospital in Toronto, says more money and time needs to be spent on looking for new drugs for influenza, which masks will truly protect people, how sick people will be cared for when there aren’t enough health-care workers and getting Canadians to agree on “fair and reasonable” distribution of vaccines.
In what is being described as the first large-scale mapping of bird flu viruses, researchers from St. Jude mapped 2,196 bird flu genes culled from ducks, gulls, shorebirds and poultry samples collected over 30 years, looking for patterns and comparing them to human flu bugs.
They also mapped the complete genome for 169 bird flu viruses. The work doubles the amount of genetic information available on avian flu.
The team honed in on a gene called NS 1. After looking at nearly 1,200 bird, human and swine NS 1 proteins, they found a particular feature of that gene which is unique in bird viruses and different from human ones.
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.
Heard this on the radio yesterday, and shuddered.
I thought that all flu viruses originated in birds. If not, where did they come from? What is the difference between a bird flu virus and a human flu virus? Does it become human once there is h2h? Dumb questions, I know!
it becomes more human, if there is h2h.
They usually came from birds earlier or later (but probably not always ?)
and often go to pigs,horses,etc. first before it jumps to humans.
I think virii are older than birds in evolution.
here are some differences:
Gene,Residue no.,Avian,1918,HumanH1N1,HumanH2N2,HumanH3N2,Swine,Horse
PB2,199,A,S,S,S,S,S,A
PB2,475,L,M,M,M,M,M,L
PB2,567,D,N,N,N,N,D,D
PB2,627,E,K,K,K,K,K,E
PB2,702,K,R,R*,R,R,R,K
PB1,375,N/S/T+,S,S,S,S,S,S
PA,55,D,N,N,N,N,N,N
PA,100,V,A,A,A,A,V,A
PA,382,E,D,D,D,D,D,E
PA,552,T,S,S,S,S,S,T
out of three A/PR/8/34 sequences have a Lys residue.
+ The majority of avian sequences have an Asn residue at position 375 of PB1,18%
have a Ser residue,13% a Thr residue
(http://www.nature.com/nature/journal/v437/n7060/fig_tab/nature04230_T1.html)
closed for volume issues. Note date of last post.