1918 epidemic more like bird flu than...

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Registered: 03-23-2003
1918 epidemic more like bird flu than...
4
Fri, 02-06-2004 - 12:22pm
SEATTLE POST-INTELLIGENCER
http://seattlepi.nwsource.com/national/159542_historicflu06.html

1918 epidemic more like bird flu than was thought

Friday, February 6, 2004


By LAURAN NEERGAARD
THE ASSOCIATED PRESS


WASHINGTON -- The 1918 flu that killed 20 million people appears to be more birdlike than previously thought, according to findings by U.S. and British researchers that could help explain why it was the deadliest influenza strain recorded.


The work doesn't have direct implications for Asia's current outbreak of bird flu, a strain that doesn't seem able to easily infect many people.


But the findings, to be published today by the journal Science, do highlight how important it is to monitor avian flu -- because the research suggests it might take fewer genetic adaptations than once thought for a bird virus to begin spreading from person to person.


The research, conducted separately by scientists at the Scripps Institute in La Jolla, Calif., and at Britain's Medical Research Council, used lung samples preserved from victims of the 1918 flu to reconstruct a protein crucial to their infection.


"These were not little steps but big strides toward understanding, at the structural and molecular level, what it is about these strains that makes them dangerous," said Dr. Gregory Poland, a flu specialist at the Mayo Clinic who reviewed the research.


The findings don't completely explain the 1918 strain's virulence, cautioned Michael Perdue, who investigates avian flu at the Agriculture Department's Agricultural Research Service. Other factors than the protein studied, called hemagglutinin, play a role too, he said.


Different influenza strains spread around the world annually. Usually, they're similar to ones that have spread previously. Every so often, a new strain tough enough to kill millions emerges, and experts believe the world is overdue for another pandemic. Unraveling what made the 1918 flu so vicious could help doctors better react if a similar strain returns.


All flu viruses are thought to have originated in birds. But scientists also have long thought that to cause human epidemics, the viruses first had to jump from birds to pigs, where genetic changes that allow the strains to better spread in mammals occur.


Flu strains that are more birdlike are more dangerous to people because their immune systems haven't been exposed to them before. Asia's current bird flu, a strain known as H5N1, clearly can jump directly from poultry to people -- at least 16 people have died of it this winter.


In the new research, scientists reconstructed the three-dimensional structure of the hemagglutinin protein, a protein on the surface of the flu virus that allows it to attach to and penetrate lung cells.


Hemagglutinin from human and bird flu viruses interacts with different cell receptors, which is why it is rare for birds to infect people.


But the new studies show the structure of hemagglutinin from the 1918 flu changed to make it capable of attaching to human cells, yet retained features primarily found in avian viruses, not human or pig strains. The findings don't rule out a brief stop in pigs before the 1918 flu took off in people, said molecular biologist Ian Wilson, lead investigator of the Scripps team.


But "we want to know how many differences there have to be to an avian flu in order to infect the human," he added. The research suggests not all that many differences are required, if they're in the right spots.


© 1998-2004 Seattle Post-Intelligencer


iVillage Member
Registered: 03-18-2000
Fri, 02-06-2004 - 12:39pm

Bird flu found in pigs as human death toll rises.


http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2004/02/06/uflu2.xml&sSheet=/portal/2004/02/06/ixportaltop.html


Two more people have died in Vietnam of bird flu, taking Asia's death toll to 18, as new tests show that the virus may have spread to pigs.





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The Food and Agriculture Organisation annoucned today that it has conducted initial tests on the region's pigs and found a potentially deadly new strain present in some of the animals. The Vietnamese government says it is unaware of any such findings.


The H5N1 virus is believed to have been detected in the nasal cavities of the pigs. Blood tests on the animals have now been sent to Hong Kong for further tests and results are pending.


The finding is alarming because pigs can become a "mixing vessel" for the flu virus. The immune system of pigs is similar to that of humans and the animals suffer from a wide variety of diseases that also infect people.


Scientists say the bird flu pathogen could swap genes with a human influenza virus inside a pig.


The World Health Organisation has said this could result in the emergence of a new subtype of virus for which humans would have no immunity.

cl-Libraone





 


Photobucket&nbs

iVillage Member
Registered: 03-23-2003
Fri, 02-06-2004 - 3:27pm
Lovely...looks like it may be a race between what the scientists can come up with for protection and how fast the virus might mutate...

iVillage Member
Registered: 03-18-2000
Sun, 02-08-2004 - 7:54am

Bird flu hits U.S., poultry culled.


Delaware's agriculture secretary says it is "way premature" for South Korea to ban U.S. poultry products after a strain of bird flu not known to affect humans was found on a farm in the state.


Michael Scuse told CNN the infected flock of about 12,000 birds -- all destroyed Saturday morning -- belonged to a private farmer who sold chickens in live markets in New York city.


More..........

 


Photobucket&nbs

iVillage Member
Registered: 03-23-2003
Fri, 02-20-2004 - 12:18pm

http://seattlepi.nwsource.com/national/apscience_story.asp?category=1500&slug=Asia%20Bird%20Flu


Friday, February 20, 2004 · Last updated 8:46 a.m. PT


Asia's bird flu strikes house cats


By DANIEL COONEY
ASSOCIATED PRESS WRITER


BANGKOK, Thailand -- Bird flu has jumped to new species in Asia, killing three house cats and infecting a white tiger in Thailand, a Thai veterinarian said Friday. U.N. health officials cautioned the cases were not confirmed.


Thai officials said the pet cats in Nakhon Pathom province outside Bangkok were the first domesticated mammals known to have contracted the disease in the current outbreak.


Thai veterinarian Dr. Teeraphon Sirinaruemit also said a white tiger at Khao Khiew zoo near Bangkok was found to have the virus but has recovered and is healthy. The zoo is the same where a clouded leopard died of bird flu last month, the first mammal apart from humans known to have died from the virus this year.


The Rome-based U.N. Food and Agriculture Organization warned that the reports on the domestic cats "require more careful scientific analysis" and for now it cannot verify that the animals died of bird flu.


In Geneva, World Health Organization spokesman Dick Thompson said that even if the cases were confirmed, there probably would not be a high risk associated with domestic cats being infected. They would be hit by the same avian influenza as birds, which does not pass easily to humans, he added.


"It isn't the kind of animal we would be worried about as a mixing vessel - like we would be if we saw the infection in pigs, for instance," Thompson said.


Health experts are concerned about the bird flu sickening other animals, in part because that could prompt mutations in the virus that in turn could make it easier to pass among people. That concern holds especially for pigs because of their genetic similarities to humans.


The virus has killed at least 22 people in Thailand and Vietnam, while infecting birds in 10 Asian nations. A World Health Organization official said it's possible that Indonesia could have human cases despite government claims to the contrary.


"It's such a large country and such a large population ... it may have been diagnosed as ordinary pneumonia," the WHO official, Georg Petersen, said.


The reported infection of three cats in Thailand has raised fears that the disease could spread from pets to humans, WHO virus expert Dr. Prasert Thongcharoen said.


So far, cases in people have been traced largely to direct contact with infected chickens, other birds or their waste.


The head of the Food and Agriculture Organization urged international cooperation in fighting bird flu, warning it could spread to more animals.


"It's quite a serious problem," FAO Director General Jacques Diouf said. "Unless we deal with it very seriously, there is the risk not only of other birds contracting it but also other animals, and naturally we have also seen the effect on humans. That's why it is necessary that we cooperate together in the region."


Canadian officials are testing samples of a mild bird flu virus that has been detected and isolated on a British Columbia farm, Canadian Health Minister Pierre Pettigrew said.


Dr. Danuta Skowronski of the British Columbia Center for Disease Control said the outbreak of the H-7 avian flu is "certainly not" the same version of the virus that has hit poultry stocks and killed people in Asia, which is known as the H5N1.


News of the British Columbia outbreak prompted Japan and Hong Kong to immediately place temporary bans on the imports of poultry products from there, officials said.


Officials in Delaware and New Jersey also are tackling an outbreak of H-7 in poultry. That version of the virus does not typically infect humans, according to the Centers for Disease Control and Prevention.