Role of wild birds disputed in avian flu outbreak mystery
Health Lorna Benson ? Mar 1, 2016
...
Last year, in a massive hunt for the source of bird flu, the Minnesota Department of Natural Resources tested more than 6,200 wild bird samples, mostly droppings, for signs of the virus.
The search turned up only two infected birds and neither was a waterfowl.
"We certainly did the best that we could using the tools that we had to describe infection. We just didn't find it," said Lou Cornicelli, wildlife research manager at the DNR.
...
"Despite the industry pointing its finger at the wild birds, it's just not there," said Michael Osterholm, who directs the Center for Infectious Disease Research and Policy at the University of Minnesota. "It was not the source of widespread transmission to many operations throughout the Upper Midwest."
...
Backyard poultry flocks should have been hit hardest because those birds were most exposed to migrating waterfowl. Instead, those birds were largely spared, he said.
Osterholm also said the lone Pope County case popped up before wild ducks and geese had even traveled through the area.
...
Osterholm said that points to a different theory worth checking ? that a non-fatal version of the virus circulated undetected among flocks that aren't tested frequently, such as layer hens. And then at some point mutated to the highly pathogenic H5N2 that laid millions of birds to waste.
...
University of Minnesota avian flu expert Carol Cardona has come to agree the idea that migrating ducks and geese brought bird flu to Minnesota isn't holding up.
On the other hand, Cardona rejects the notion that the deadly virus came out of the industry's poultry barns.
Under that scenario, she said there would have been much less genetic variation in the bugs that caused more than 100 flock infections.
"It wasn't just a static thing. There was evolution in the virus," Cardona said.
The U.S. Department of Agriculture identified dozens of different versions of the virus that popped up in Minnesota.
Cardona said it's still possible the virus traveled in another wild bird species that hasn't been tested yet.
...
Health Lorna Benson ? Mar 1, 2016
...
Last year, in a massive hunt for the source of bird flu, the Minnesota Department of Natural Resources tested more than 6,200 wild bird samples, mostly droppings, for signs of the virus.
The search turned up only two infected birds and neither was a waterfowl.
"We certainly did the best that we could using the tools that we had to describe infection. We just didn't find it," said Lou Cornicelli, wildlife research manager at the DNR.
...
"Despite the industry pointing its finger at the wild birds, it's just not there," said Michael Osterholm, who directs the Center for Infectious Disease Research and Policy at the University of Minnesota. "It was not the source of widespread transmission to many operations throughout the Upper Midwest."
...
Backyard poultry flocks should have been hit hardest because those birds were most exposed to migrating waterfowl. Instead, those birds were largely spared, he said.
Osterholm also said the lone Pope County case popped up before wild ducks and geese had even traveled through the area.
...
Osterholm said that points to a different theory worth checking ? that a non-fatal version of the virus circulated undetected among flocks that aren't tested frequently, such as layer hens. And then at some point mutated to the highly pathogenic H5N2 that laid millions of birds to waste.
...
University of Minnesota avian flu expert Carol Cardona has come to agree the idea that migrating ducks and geese brought bird flu to Minnesota isn't holding up.
On the other hand, Cardona rejects the notion that the deadly virus came out of the industry's poultry barns.
Under that scenario, she said there would have been much less genetic variation in the bugs that caused more than 100 flock infections.
"It wasn't just a static thing. There was evolution in the virus," Cardona said.
The U.S. Department of Agriculture identified dozens of different versions of the virus that popped up in Minnesota.
Cardona said it's still possible the virus traveled in another wild bird species that hasn't been tested yet.
...
Comment