Scientists still at a loss to explain spread of avian flu

[Emily]

[h=1]Anderson: Breeders hope game birds can dodge lethal flu[/h] The North American Gamebird Association lists 15 breeders of pheasants, chukars and other game birds in Minnesota. To date, none has been hit with bird flu.
May 29, 2015 ? 12:55am

Dennis Anderson
...
Only two regional wild birds are known to have died from the H5N2 bird flu strain this spring, Minnesota Department of Natural Resources research director Lou Cornicelli said Thursday. One was a snowy owl found in Wisconsin, the other a Cooper?s hawk in Yellow Medicine County, in western Minnesota. ?For me, it was interesting that it was a Cooper?s hawk,? Cornicelli said. ?Cooper?s hawks don?t generally eat waterfowl. They eat small birds and some small mammals.?
Added Cornicelli: ?If, on the other hand, we had found the disease in a peregrine falcon or an eagle, we could surmise they picked it up from eating a wild duck.?
Researchers believe the disease is carried by ducks and geese and spread through their feces. Waterfowl themselves remain unaffected.
One theory about the strain?s origin suggests a form of bird flu originating in Asia traveled in waterfowl to Alaska, where it perhaps mixed with another strain carried by ducks and geese migrating along the North American Pacific coast. The H5N2 strain was then perhaps brought to Minnesota and neighboring states this spring by migrating waterfowl.
?I hear that, but we just don?t know,? Cornicelli said. ?We know at least 144 strains of avian influenza are carried by waterfowl. What we don?t know is what role waterfowl played in the spread of the H5N2 disease to domestic turkeys and chickens.?
DNR staff this spring collected 3,138 samples of duck and goose feces from various parts of the state and tested them for the virus. They also tested 83 hunter-killed wild turkeys.
One hundred of the waterfowl feces samples were positive for more harmless strains of bird flu, but not H5N2.
?Finding low pathogenic flu strains in waterfowl is fully expected,? Cornicelli said. ?For us, it confirmed that fecal sampling works as a surveillance method.?
No trace, meanwhile, was found in the turkeys...

http://www.startribune.com/breeders-hope-game-birds-can-dodge-lethal-flu/305412131/

 

[Emily]

By Scott Kraus Of The Morning Call
May 29, 2015
...
In 1983, the last time a highly pathogenetic strain of the virus was detected here, 17 million birds had to be destroyed in what was at the time the nation's worst outbreak.
... Leon Moyer, co-owner of Moyer's Chicks in Quakertown, has vivid memories of the 1983-84 bird flu epidemic, when entire counties such as Lancaster were quarantined, with no chickens or chicken products allowed in or out.


Authorities quickly learned how easily the flu spread, he said. In the beginning, Moyer said, contaminated flocks were gassed, piled into dump trucks and thrown in landfills.
"All along the route to the landfill, flocks were coming down with the virus," he said.
Farmers were ordered to simply dig a hole and bury their dead chickens on their property....

http://www.mcall.com/news/breaking/mc-pa-bird-flu-outbreak-20150529-story.html#page=1

 

[Pathfinder]

Scientists race to decode secrets of deadly bird flu

Wild birds brought it from Asia to Midwest, but its rapid spread is unprecedented in U.S.

By Josephine Marcotty Star Tribune JUNE 8, 2015 ? 6:02AM

The worst avian flu outbreak in the nation?s history has spawned a series of investigations by Minnesota disease researchers to figure out why this new and exceptionally deadly virus is behaving in such bizarre ways.

Because at this point, scientists are baffled.

?This situation is throwing all the old dogma out the window,? said Michael Osterholm, an infectious disease specialist at the University of Minnesota who advises the turkey industry.
...
The outbreak, which has so far decimated poultry operations and sent egg prices soaring, also provides a stark warning that flu viruses are unpredictable and can swiftly mutate from benign to dangerous. This strain has been moving around the globe for years, crossing and mixing among many species of birds ? proving lethal to some and relatively harmless in others. And though it presents a very low risk to people, no one knows if or when that could change.

?If there is any disease that?s incredibly humbling, it?s influenza,? Osterholm said. ?Every time you think you know it, you are reminded that Mother Nature is in charge.?
...
This outbreak is, in a sense, a continuation of one that began in China in 1996. The virus stayed there for seven years, but then began an unprecedented spread across Europe and Africa. It has changed over time, affecting both wild and domestic birds, but genetic testing shows that the H5 component that arrived in Minnesota has Asian lineage, said Suarez.
...
Initially, farmers and scientists assumed it was spreading from wild birds into the poultry barns...

?It could have been introduced? in wild birds, Osterholm said. ?But there is something else amplifying it.?
...

http://www.startribune.com/scientists-race-to-decode-secrets-of-deadly-avian-flu-strain/306436121/