Emergence of Highly Pathenogenic Flu in the Pacific Northwest (H5N1, H5N2 and H5N8)
A Highly Pathenogenic Strain of
Avian Flu (WHO),
H5N1, has appeared in Whatcom County, Washington, in the Pacific Northwest, according to a
report filed by Dr John Clifford, United States Department of Agriculture with the World Organisation for Animal Health (
OIE). The report was filed 1/20/2015 for an event starting on 12/29/2014. The incident involved a
Green-winged Teal:Anatidae (Anas carolinensis).
The H5N1 strain's Eurasian lineage genes ( (PB2, H5, NP, MP) are over 99% identical to a
gyrfalcon H5N8 strain found in Whatcom County. It's North American lineage gene PB1 is 98% identical to a
Northern Pintail H5N2 strain also found in Whatcom County, while other North American lineage genes (PA, N1, NS) are of low pathenogenicity (LPA I), according to the report filed with the
OIE. This strain is a novel strain, and is different than strains appearing in Asia.
Discussion by
Recombinomics raises "the possibility of multiple constellations with the H5N2 sero-type"
The Pacific Northwest has experienced H5N2 and H5N8 strains during this fall and winter season in bird populations, as indicated by the
US Department of Agriculture.
Birds affected by avian flu this fall/winter 2014/5 season have included:
H5N1: Green-winged Teal, Whatcom County, Washington.
H5N2: Northern Pintail (Whatcom County, Washington), Broiler, Table Egg Layer, Turkey, chickens (Southern British Columbia), ducks and geese (Clallam County, Washington), mallard (Fern Ridge, Oregon), falcons (Canyon County, Idaho), turkeys, chicken, guinea fowl, water fowl (Benton County, Washington) .
H5N8: guinea fowl, chickens, ducks, geese (Winston, Douglas County, Oregon) , Wild Ducks (Idaho), grylfalcons, American Wigeon. guinea fowl, chickens, ducks and geese (Whatcom County, Washington)
The distribution of
H5N2 and
H5N8 in the Pacific Northwest shows an interesting pattern. Whatcom County, adjacent to the border between Washington State and British Columbia (Sumas-Lynden border crossing) offers an opportunity for mixing of the various avian flu types, given
migratory paths and poultry stocks in the area. Other areas of concentration include Benton County, Washington, near Hanford, Washington as well as areas in Oregon and Idaho.
Avian Flu has a considerable impact on bird populations. There have been limited cases of H5N1 in the human population, although one did occur in 2014 resulting from
a flight from Beijing to Vancouver Canada and on to Edmonton.
Avian influenza is a disease naturally occurring in wild aquatic birds which can infect domestic poultry and other bird and animal species. It is very difficult for humans to become infected by avian influenza, although there have been some limited human cases. H5N1 is sustained in the avian (bird) population but not is not currently sustained in the human population.
There has been
one human death from H5N1 in North America. On
December 27, 2013, a woman travelling from Beijing, China, to Vancouver, B.C. and then onto Edmonton, Alberta, Canada, became ill on the Beijing to Vancouver leg of the flight. She was admitted on January 1, 2014 to an Edmonton hospital and died two days later.
The
Centers for Disease Control and Prevention (CDC) is the lead U.S. Agency for the management of health issues and has information on
Avian Flu.
Recombinations and reassortments of influenza viruses provide potential opportunity for the development of new strains or of human to human transmission. The occurrence of
H5N1,
H5N2 and
H5N8 in the Pacific Northwest in the fall-winter 2014-5 season raise interesting questions as to the development of the one H5N1 case identified this season and as to whether there is any relationship with the H5N1 death which occurred in the prior (2013-2014) fall-winter season.
It is interesting to consider various factors which may account for the development of highly pathenogenic avian influenza in the Pacific Northwest. These considerations may involve the locations in which the birds were found, migratory patterns, climate change, environmental factors, and the availability of reservoirs and vectors in which the virus can mix, spread and potentially become sustained in various host or intermediate host various populations.
Marilyn Dunstan Photography
Mallard Duck Flying
Ducks
Centers for Disease Control & Prevention:
CDC
CDC-Avian Flu
Human Infection with Avian Influenza A (H5N1) Virus
World Health Organization:
WHO
WHO-Avian Flu
World Organisation for Animal Health (
OIE)
Gyrfalcon H5N8
Northern Pintail H5N2
