Low-risk H5N1 bird flu in Ohio wild birds- USDA

LPAI H5N1 ("North American" H5N1)

 

 

Which viruses cause highly pathogenic disease?

Influenza A viruses¹ have 16 H subtypes and 9 N subtypes². Only viruses of the H5 and H7 subtypes are known to cause the highly pathogenic form of the disease. However, not all viruses of the H5 and H7 subtypes are highly pathogenic and not all will cause severe disease in poultry.

On present understanding, H5 and H7 viruses are introduced to poultry flocks in their low pathogenic form. When allowed to circulate in poultry populations, the viruses can mutate, usually within a few months, into the highly pathogenic form. This is why the presence of an H5 or H7 virus in poultry is always cause for concern, even when the initial signs of infection are mild.

 

Curt,

 

In my opinion, you are 100% correct. It is called deception and it is done on purpose. people take formal training on how to do this. I was one of them.

 

By saying they found low path and by saying they didn't find the hi path strain from asia, most people assume they didn't find hi path, but that is not what is being said.

 

Like I said a long time ago. It is more important to pay attention to what they don't say and how they don't say it.

Thanks for that quotation.  I see now why you find low path alarming.

However, considering the history of spread in Asia, the genetics, etc. I think the danger from low path in North America is much less worse. 

2 reasons:

 

1) In a more detailed document at the WHO site (and I think others there),

http://www.who.int/csr/don/2004_03_02/en/
"When the virus was allowed to continue circulating in poultry, it eventually mutated (within 6 to 9 months) into a highly pathogenic form with a mortality ratio approaching 100%." 

So having an introduction of low path becomes a danger if not noticed or not treated in birds.  In the US and Canada there is a lot of bird surveillance and especially poultry, so there are never months going by where poultry are passing LPAI to each other.

 

2) At present we rightly fear increased transmissions from humans to humans in places like Indonesia.  This requires MORE mutations to happen that favor the spread, and more mutations of course could alter the virus in other ways such as making it less lethal.  If LPAI H5N1 was in North America, it would first have to go through several months of mutations to adapt well to poultry.  This would not adapt it to humans.  THEN it would still have to mutate further to adapt to human spread.

 

There is much more danger to us from it going human to human in a strain in Asia that is already high path in birds.

 

Low path H5N1 has been conirmed in US. This verifies that Hi path can mutate from low path and the times it has, it has not been the same hi path virus found elsewere.

 

It gives plausibility to the hole in the press releases talkied about in other threads about the possibility that the is a high path virus in the US that is not the same as the HIgh path virus in asia.

Bird flu may wing its way to local shores

By RICHARD DEGENER Staff Writer, (609) 463-6711
Published: Tuesday, March 14, 2006
Updated: Tuesday, March 14, 2006
http://www.pressofatlanticcity.com/news/local/capemay/story/6025984p-5998956c.html

CAPE MAY — One of the area's biggest tourist industries and a dangerous virus sweeping Asia, Europe and Africa may be on a collision course with a meeting date sometime next fall.

Millions of dollars are spent each fall as tourists come here to observe migratory birds heading south. Scientists with the U.S. Geological Survey, however, are worried some of those birds may carry the deadly avian flu virus, more commonly known as bird flu. They are concerned because North American birds go up to Alaska, Canada and Russia during the summer and mix with birds from Asian flyways. A few North American species even winter in Asia.

While most scientists believe the bird flu would likely come down from Alaska via the Pacific Flyway, and not down the Atlantic Flyway that passes New Jersey, there is a strong belief that it will come with migratory birds. There is evidence bird migrations are helping move the flu around Asia, Europe and Africa already. More reports are coming in of the virus being in migratory birds. Will they bring it here?

“It's probably not if, but when,” said Leslie Dierauf, director of the USGS National Wildlife Health Center in Wisconsin.

Dierauf said Congress has given the USGS and other federal agencies $12 million to test wild birds for the virus, a program that began in August and which serves as an early-warning system of the arrival of the virus. A meeting is taking place in Ohio next week so the councils that oversee the flyways can decide where to test and what birds to sample. Testing done thus far has found a low-pathogen virus in 10-percent of the birds sampled, but none have had the deadly H5N1 strain blamed for sickening 147 people and causing 78 deaths, mostly in southeast Asia.

Most of those deaths have been blamed on contract with domestic birds. The concern is that the virus has caused death in more than 60 species of wild birds, and when the virus jumps to new species it can mutate. The main concern is it could mutate into a virus that is easily transmitted among humans. That could cause the first global influenza pandemic since World War I.

“Migratory birds are reservoirs for the virus, but they usually don't get sick. When the low-pathogen virus mixes with domestic birds, it becomes highly pathogenic and kills poultry,” Dierauf said.

What's more disturbing in this case is that the newly created virus has then gone back to wild birds.This had previously happened only one time before on a large scale, in 1961 in South Africa, Dierauf said. It happened last spring in Qinghai, China when as much as 10 percent of the known population of bar-headed geese died of H5N1.

“We're worried about people, the poultry industry and wild birds. The key is to keep wild birds separate from domestic birds so they don't mix. When they mix, something peculiar happens genetically that nobody can really explain yet,” Dierauf said.

Peter Dunne, who directs the New Jersey Audubon Society's Cape May Bird Observatory, said it would be impossible to control the wild bird population. He said it wouldn't succeed and it would do a lot of damage

“This is the natural world in motion. Objecting to this is like saying, ‘Stop the world, I want to get off,' ” Dunne said.

The list of the most worrisome species also reduces Dunne's concern for the East Coast. Dierauf said the biggest concern on the Atlantic Flyway are the horned grebe, tundra swan and greater scaup. Dunne said the horned grebe is “a regular here,” but the greater scaup and tundra swan are not common.

Other waterfowl species of concern, birds that mix in the north with Asian birds, are the whooper swan, emperor goose, black brant, and Aleutian Canada goose. Dunne said none are regulars here.

Shorebirds of concern include the Pacific golden plover, black-bellied plover, semipalmated plover, black-tailed godwit and marbled godwit. There are also three loon species that will be tested, including red-throated, yellow-billed and Pacific Arctic loon. Dunne said even in cases where some of these birds frequent the East Coast, the population is often separate from the those birds heading down the Pacific coast, which are mixing in Alaska and Siberia.

“It would be tantamount to listening to traffic reports from Los Angeles and getting concerned about road closings,” Dunne said.

The prevailing westerly winds on the East Coast actually serve to blow more North American birds to the Old World rather than vice versa. One exception is the Northern wheatear, which migrates from the Northeast polar region to Africa.

Still, Dunne acknowledges any disease that gets to this continent could spread across it.

“We're bird experts, not flu experts,” Dunne said.

The bird flu first arose in 1997 in Asia and has since become the largest and most severe outbreak among poultry ever recorded. The people who got it had contact with domestic birds. No cases of transmission between humans has been recorded.

There is concern the virus could find other ways to America, such as travel by infected people and illegal smuggling of birds.



To e-mail Richard Degener at The Press:

RDegener@pressofac.com