Avian Influenza in Wildbirds
Many strains of avian influenza viruses occur naturally in wild birds. Some of these strains can be spread to domestic birds
(poultry in particular, especially ducks, chickens and turkeys). Strains that develop in poultry may lead to the deaths
of the domestic birds.
Currently, one strain found in wild and domestic birds in Europe, Asia and Africa has the potential to kill large numbers
of domestic birds, and rarely, infected humans. There is no evidence that this strain is in North American birds. However,
mixing of Eurasian and North American birds in Arctic breeding areas could lead to this strain coming into Alberta with
migrating birds in late summer and fall.
The Alberta government is implementing plans for appropriate surveillance of wild birds in conjunction with national surveillance
programs. Details are included in frequently asked questions shown below or view a printable pdf. The key points of the surveillance efforts are as follows:
between July 15 and November 30, 2006,
the bird species considered suitable include waterfowl (ducks, geese, swans) and birds of prey (hawks, eagles, owls),
A report on the 2006 surveillance efforts has been completed. A total of 83 found-dead birds was tested. Only three birds
(2 gulls, 1 mallard) were found to have low pathogenic strains of avian influenza. No evidence was found of the highly pathogenic
H5N1 strain, which has caused mortality in parts of Asia, Europe and Africa. The report is available as Surveillance for High Pathogenic Avian Influenza in Dead Wild Birds in Alberta, 2006.
Frequently Asked Questions
What is avian influenza?
Avian influenza viruses are common infections in wild birds, primarily waterfowl. They usually do not cause disease in wild
species but spread occasionally to domestic birds (ducks, chickens, turkeys) in which they can develop into strains that
cause significant mortality in domestic species. Rarely, some strains can be passed from domestic poultry to humans. In
addition, swine (pigs) can be infected with some strains of avian influenza viruses. Avian influenza viruses are not the
same as the human influenzas (common “flu” viruses) that are passed around every year in people.
How are influenza viruses named?
All viruses contain genetic material wrapped in a protein coat. Influenza viruses are separated into types based on two
of the proteins in this coat: hemagglutinin (H) and neuraminidase (N). Strains of influenza viruses are named according
to the type of H and N proteins that they contain as well as where they occur. For example, the strain of greatest current
concern around the world is known as Eurasian H5N1. In addition, the mortality that strains cause in chickens is an indication
of “high” or “low” pathogenicity (often shortened to high path or low path). Eurasian H5N1 is highly pathogenic to poultry.
However, there are other strains of H5N1 that are not high path.
What is going on in Eurasia with respect to avian influenza?
Eurasian high path H5N1 avian influenza was first described in Hong Kong in 1996. Since then it spread in poultry and domestic
waterfowl populations throughout Southeast Asia. In 2005, the virus appears to have spread to wild, migratory waterfowl,
leading to outbreaks in waterfowl in China and Mongolia. Now the virus has been identified in several other countries in
Central Asia, Eastern Europe, Western Europe, and Africa. The strain is thought to spread via the legal and illegal international
trade in domestic birds and bird-related products, and to a lesser extent by migratory waterfowl. Millions of domestic birds
have been and continue to be culled in an attempt to stop the spread of the virus, and 192 humans are known to have contracted
Eurasian H5N1, 109 of whom have died (as of 6 April 2006). It is important to note this strain does not spread efficiently
from human to human and to date no one has been infected directly from a wild bird.
What do we know about avian influenza in North America?
Avian influenza viruses have been monitored in North America for 30 years, including surveillance sites in Alberta. These
studies show that:
low pathogenic strains are common in North American waterfowl
high pathogenic strains have not been isolated from wild birds in North America, and even the subtypes that evolve to high
path strains (H5 and H7 subtypes) are very rare, particularly in birds that migrate through Alberta
the viruses are more frequent in juvenile birds than adults and frequency differs among species
virus frequency is variable from year-to-year and even month to month
Will the high pathogenic H5N1 virus come to North America from Eurasia?
There is concern that mixing of Eurasian and North American birds in arctic breeding areas could potentially bring high
pathogenic Eurasian H5N1 to North America. However, genetic studies of influenza viruses indicate this is relatively unlikely.
Eurasian and North American waterfowl maintain distinct strains of avian influenzas. This suggests there is limited sharing
of influenza virus, at least as shown by the previous strains in waterfowl. However, both the United States and Canadian
governments are being diligent in establishing monitoring programs to look for high pathogenic H5N1.
What is Sustainable Resource Development doing about avian influenza?
Representatives from SRD Fish and Wildlife participate in the provincial Avian Influenza planning committee. Our programs
and informational materials are reviewed by this group to ensure support by the health and agriculture members.
Sustainable Resource Development, in conjunction with Alberta Agriculture, Food and Rural Development (AFRD), will implement
a surveillance program in wild birds as follows:
July 15 through November 30, 2006
test dead waterfowl, particularly swans and raptors
investigate reports of unusual bird mortality, and if appropriate, submit carcasses to AFRD for testing
collect tissues from crows and magpies that test negative for West Nile virus and provide them to the national avian influenza
provide Alberta-specific information on our wildlife disease web pages
What do I do if I find a dead wild bird?
Most bird species are not suitable for avian influenza surveillance (for example all songbirds, woodpeckers, and blackbirds).
Effective surveillance should focus on the species most likely to be affected, and even then it is not necessary to test
all individuals of these species. If high pathogenic Eurasian H5N1 arrives in Alberta, it is most likely to be found in
dead waterfowl (particularly swans) and raptors (hawks, owls, eagles). Clusters of unusual mortality should
be reported to a Fish and Wildlife office. Call toll-free 310-0000 to get the phone number of the closest
As a general guideline, members of the public should avoid handling live or dead wild birds. If handling can't be avoided,
wear disposable gloves, place a plastic bag over your hand before picking up the dead bird, or shuffle the dead bird into
a box or container without touching it (for example, use a stick to move the bird). Wash your hands with soap and water,
and disinfect using alcohol, diluted bleach, or commercial disinfectants any surface that has come in contact with dead
Is is still safe to hunt waterfowl?
Yes. There is no reason to believe that healthy flying waterfowl are infected with avian influenzas that pose any risk to
hunters. To date, Eurasian highly pathogenic H5N1 avian influenza has not been found in North America and no person has
been infected with this strain directly from wild birds. Of course, normal hunting and gun safety precautions should be
followed at all times.
What would happen if highly pathogenic strains of avian influenza were found in wild birds in Alberta?
All H5 and H7 subtypes of avian influenza must be reported to the Canadian Food Inspection Agency. If subsequent tests identify
high path H5N1, the public as well as provincial, territorial, and federal agriculture, health and wildlife agencies would
be notified. Visit the web pages provided herein to find out what follow-up actions are planned by Canadian Food Inspection
Agency, Alberta Agriculture, Food and Rural Development, and Alberta Health and Wellness. The Fish and Wildlife Division
of Alberta Sustainable Resource Development will continue to monitor mortality in wild waterfowl, particularly the species
and in the geographic area in which the high path strain was detected.
If highly pathogenic strains of avian influenza were found in wild birds in Alberta, would the government cull wild birds?
No. Culling of wild birds is inefficient and ineffective in reducing the health risks to poultry or the secondary health
risks to humans.
How does the avian influenza virus commonly found in wild birds relate to pandemic influenza?
Pandemic strains of avian influenza are so named because they readily spread among humans and often cause fatal infections.
Pandemic strains are extremely rare and currently none exist anywhere in the world. The World Health Organization and many
other health agencies are concerned that high path Eurasian H5N1 in people could evolve into a pandemic strain that passes
freely from person to person and could pose serious risk to human populations. Note that the source of pandemic strains
occurs within people and not within wild birds.
For information on wildlife diseases in Alberta, including avian influenza:
For information on avian influenza from a poultry perspective, visit:
Results of Canada's 2006 survey for avian influenza in wild birds:
For information on avian influenza federal livestock perspective, visit:
For information on human influenzas, visit:
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Updated: February 12, 2007