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Avian Influenza

What is avian influenza? | Symptoms in birds | Transmission between birds | Transmission to humans | Avian influenza in Canada |
What producers can do | The CFIA’s role | What travellers can do | Can other animals contract avian influenza? | How to get more information | Latest Information

What is avian influenza?

Avian influenza (AI) is caused by the influenza virus Type "A", which can affect several species of food producing birds (chickens, turkeys, quails, guinea fowl, etc.), as well as pet birds and wild birds.

Avian influenza viruses can be classified into two categories: low pathogenic (LPAI) and high pathogenic (HPAI) forms based on the severity of the illness caused in chickens. Most AI viruses are low pathogenic and typically cause little or no clinical signs in infected birds. There are many influenza subtypes, however, only H5 and H7 subtypes are known to have become high pathogenic in avian species.

What are the signs of disease in a commercial flock?

Some or all of the following clinical signs are evident in infected birds:

• quietness and extreme depression;
• sudden drop in production of eggs, many of which are soft-shelled or shell-less;
• wattles and combs become swollen and congested;
• swelling of the skin under the eyes;
• coughing, sneezing and nervous signs;
• diarrhea;
• haemorrhages on the hock;
• a few deaths may occur over several days, followed by a rapid rise in mortality resulting in the death of the majority of the flock

Avian influenza (AI) may be suspected on the basis of clinical signs and events leading to the disease. Contact your veterinarian or the CFIA office in your area if you suspect your poultry are showing signs of AI. Producers are obligated to report any suspicion of AI because it is a reportable disease under the Health of Animals Act.

How is the disease transmitted to commercial bird flocks?

Wild birds, especially waterfowl, are natural reservoirs for the influenza viruses. Wild birds are not generally affected by the disease but can still transmit the disease to domestic birds.

The disease can also spread to birds through contact with infected poultry and poultry products, and through manure and litter containing high concentrations of the virus, for example through contaminated clothing and footwear, vehicles and equipment, and feed and water.

Is avian influenza transmissible to humans?

Avian influenza (AI) viruses, such as the highly pathogenic H5N1 virus present in Asia, may, on rare occasions, cause disease in humans. Transmission to humans has occurred by people having close contact with infected birds or heavily contaminated environments.

Due to the potential for human infection, it is recommended that those people working with or in contact with poultry suspected of being infected with AI wear protective clothing, including face masks, goggles, gloves and boots.

Visit the Public Health Agency of Canada Web site for more information on the potential effects of AI on people: www.phac-aspc.gc.ca.

Has avian influenza occurred in Canada?

In February 2004, the Canadian Food Inspection Agency (CFIA) identified the presence of a low pathogenic H7 avian influenza (AI) in the Fraser Valley area of southern British Columbia. Subsequent tests revealed the presence of highly pathogenic H7 AI in British Columbia in March 2004. The CFIA depopulated all infected premises (42 commercial and 11 backyard premises) on which highly pathogenic AI was found and pre-emptively destroyed all birds in the surrounding three-kilometre areas.

In November 2005, the CFIA identified the presence of a low pathogenic strain of H5N2 on two duck farms in the Fraser Valley. The two duck farms were depopulated and the 78 commercial bird farms within a five-kilometre radius were kept under observation for a three-week period. The surveillance period ended on December 10, 2005.

The Canadian Cooperative Wildlife Health Centre sampled more than 4,400 wild ducks for H5 or H7 AI during the 2005 fall migration period. The survey found several types of lowly pathogenic strains of H5 influenza.

What can livestock producers do to prevent infection on their farm?

Wild bird populations, a natural reservoir for the influenza viruses, are beyond producers’ control. Therefore, it is essential for commercial poultry producers to maintain strict biosecurity practices to prevent introduction of the virus in their flock.

On a farm:

• Keep poultry confined indoors
• Keep away from areas frequented by wild fowl;
• Keep strict control over access to your poultry houses by people and equipment;
• Keep equipment cleaned and disinfected before taking it into poultry houses;
• Do not keep bird feeders or create duck ponds on your property as they attract wild birds; and
• Maintain high sanitation standards.

What is the CFIA's role in controlling and preventing this disease from entering Canada?

Avian influenza (AI) is a reportable disease under the Health of Animals Act. This means that all suspected cases must be reported to the CFIA. All reported suspect cases are immediately investigated by inspectors from the agency. Avian influenza can be suspected based on clinical signs and events leading to the disease. However, since the signs and progression of AI in the flock are similar to other poultry diseases, confirmation through laboratory diagnosis is essential.

The CFIA imposes strict regulations on the import of poultry and poultry products from foreign countries. These regulations are enforced through port-of-entry inspections.

In the event of an outbreak of a foreign animal disease, the goal of the Agency’s emergency response is to prevent further spread of the disease and protect animal health. In an AI outbreak, the CFIA would employ its "stamping out" policy in an effort to eradicate the disease.

Actions include:

• The humane destruction of all infected and exposed animals;
• Surveillance and tracing of potentially infected or exposed poultry;
• Strict quarantine and controls on movement of poultry; and
• Thorough decontamination of infected premises

Canada can regain its disease free status and resume normal trade in poultry products once the disease control operations are completed and AI has been eradicated.

What can travellers do to avoid bringing the disease into the country?

While out of the country:

Avoid visiting areas where you may come into contact with live birds, such as poultry farms, live bird markets or any other area where birds congregate. This is most important in countries experiencing an outbreak of high pathogenic avian influenza (an updated list of countries affected by AI can be found at the World Organisation for Animal Health Web site at http://www.oie.int/eng/en_index.htm. If you are in contact with live birds infected with the AI virus, the virus may persist on clothing, footwear and in hair. Take appropriate personal hygiene measures including thorough hand washing and showering, wash clothing, and clean and disinfect footwear.

On returning home:

1. Ensure all birds and poultry products you wish to bring into Canada are eligible for entry and declare all animal products upon arrival.
2. Take appropriate personal hygiene measures including thorough hand washing and showering, wash clothing, and clean and disinfect footwear after arrival to ensure they are free of soil and manure.
3. Avoid visiting poultry farms upon return from a country affected by AI.

For more travel information, visit Public Health Agency of Canada Travel Medicine Program Web site at www.TravelHealth.gc.ca.

Can other animals contract avian flu?

Avian influenza (AI) typically affects species of food producing birds (chickens, turkeys, quails, guinea fowl, etc.), as well as pet birds and wild birds. Studies have shown that a small number of mammalian species, including pigs, seals, whales, mink, and ferrets, are susceptible to natural infection with AI viruses.

How to get more information

Contact the Canadian Food Inspection Agency (CFIA) area offices:

Atlantic Area:
(506) 851-7400

Quebec Area:
(514) 283-8888

Ontario Area:
(519) 837-9400

Western Area:
(403) 292-4301

You can also find the telephone number of your local CFIA office by consulting the blue pages of your local phone directory.

Public Health Agency of Canada Web site:
http://www.phac-aspc.gc.ca/influenza/avian_e.html

Health Canada Web site: http://www.hc-sc.gc.ca/iyh-vsv/diseases-maladies/avian-aviare_e.html

May 2006
P0295E-04/06