We're here for you: A message from Canadian Chicken Farmers regarding COVID-19

Food Safety

Avian Influenza – information and resources

Avian influenza (AI) cases have been popping up across the world recently, prompting many regions to implement disease prevention strategies and heighten biosecurity requirements on farms.

AI is known to spread in wild birds mainly along the wildfowl migration flyways, and the virus appears to be spreading more efficiently via migratory birds than ever. By travelling across the wildfowl flyways, AI can spread across the globe.

This map created by poultryworld.net provides a good visual of where high pathogenic AI cases are occurring and offers more information on each outbreak, including species, virus type, and date of reporting to the World Organization for Animal Health (OIE).

Given the current situation globally, this serves as a good reminder for the Canadian poultry industry that the risk of AI is very real.

 

Biosecurity is the Best Defense

The best defense against AI and other pathogens, as always, is good biosecurity:

  • Vigilance in implementing good biosecurity on farms, each and every day, is important for protecting not only your flocks, but those of your neighboring farms as well
  • Minimize direct contact between poultry farms and prevent contact with wild birds
  • Avoid non-essential personnel entries to your farm premises and barns
  • Change footwear when entering the Restricted Area and prevent wearing contaminated clothing and equipment in production areas
  • Closely monitor flock health, including mortalities, feed and water consumption, and abnormal bird behaviour
  • Immediately consult your veterinarian in cases of unexplained mortality or flock illness; submit unexplained mortalities for testing
  • Do not handle dead wild birds. Report dead wild bird sightings to the Canadian Wildlife Health Cooperative, cwhc-rcsf.ca.
  • Follow the requirements of the On-Farm Food Safety Program for biosecurity

 

Clinical Signs of Avian Influenza (AI)

Avian influenza (AI) is a contagious viral infection that can affect several species of poultry, such as chicken and turkey, as well as pets and wild birds. AI viruses can be classified into two categories – low pathogenic (LPAI) and high pathogenic (HPAI) – based on the severity of the illness caused in poultry. HPAI viruses typically cause severe illness and mortality, whereas LPAI viruses typically cause little or no clinical signs. Most AI viruses are low pathogenic; however, some subtypes are capable of becoming highly pathogenic1.

Birds affected with AI show a variety of clinical signs that may involve the respiratory, digestive, reproductive, or nervous systems.

Clinical signs of LPAI are typically mild and include:

  • Decreased food consumption;
  • Huddling, depression, closed eyes;
  • Respiratory signs (coughing and sneezing);
  • Decreased egg production.

Clinical signs of HPAI include:

  • Sudden onset of high mortality
  • Marked depression with ruffled feathers;
  • Decreased feed consumption;
  • Excessive thirst;
  • Decreased or cessation of egg production;
  • Mild to severe respiratory distress (including coughing, sneezing, and excessive eye discharge);
  • Swollen wattles and combs and watery greenish diarrhea;
  • Nervous signs are not frequently observed in poultry, but can include a lack of coordination and an inability to walk and stand.

Producers must be aware of the health status of their flocks and should consult their veterinarian upon any abnormal activity, clinical signs, or other concerns.

 

North America’s Waterfowl Flyways

There is evidence that the north-south migration of birds in North America within these geographically-based flyways plays an important role in shaping the genetic structure of populations of avian influenza viruses2. These flyways overlap and also allow the transmission of AI across North America.

The transmission of AI from wild birds to commercial flocks is a reminder for producers to be extra-vigilant during migratory seasons.

Image from Ducks Unlimited. www.ducks.org.

 

AI is not a food safety risk

There is no evidence to suggest that the avian influenza virus can be transmitted to humans through the consumption of food, notably poultry and eggs3,4. Follow the usual precautions when handling or eating poultry products: Wash hands and surfaces often, keep raw poultry separate from everything else, cook to a safe internal temperature, and chill leftovers within two hours.

 

What to do if you suspect AI on your farm

Upon suspicion of AI, producers in collaboration with their veterinarian should:

  • Implement a self-quarantine:
    • Restrict movement off the farm to prevent any infected things (poultry, poultry products or equipment) from leaving the property
    • Restrict movement onto the farm, and ensure that strict biosecurity measures are taken for any movement that does occur
  • Call their veterinarian and provincial board office
  • Call the CFIA Animal Health District Office

CFIA staff will visit your farm to begin an investigation and implement a quarantine (also called a Declaration of Infected Place) to control the potential spread of disease. Documentation will be provided outlining the rules of the quarantine, and any other farms with significant links may also be place under quarantine.

Wear personal protective equipment (PPE) when going into a suspect or confirmed barn with AI, or dealing with mortalities from those premises.

 

What to do if your farm is under quarantine

While your property is under quarantine, you will have the following responsibilities5:

  • Request CFIA permission to move birds, bird products, bird by-products and poultry related equipment on or off the property.
  • Ensure that footwear and vehicles leaving the property have been cleaned and disinfected.
  • Apply strict biosecurity measures for yourself and any employees.
  • Maintain fences and gates around the farm to control the movement of people on and off the premises.
  • Where applicable, maintain fences and gates to areas housing birds—all birds should be housed indoors while the quarantine is in place.
  • Report all sick and dying birds, and any that escape the farm.
  • Implement vermin, feral animal, or wildlife control measures if warranted.
  • Keep dogs, cats and other household pets confined.
  • Inform all persons entering the farm of the quarantine.
  • Limit on-farm visitors to essential services.

Testing will be done as quickly as possible to confirm if the birds are infected with AI. Samples will be taken from the flock and sent to a CFIA-approved laboratory.

 

What happens if AI is confirmed on your farm or on a neighbouring farm?

CFIA has a webpage which details the steps that will be taken if your flock is infected with AI.

While all disease response situations are different, the steps involved in an AI response usually include the following:

  • Movement restrictions, e.g., quarantines
  • Sample submission
  • Investigation
  • Destruction and disposal
  • Cleaning and disinfection
  • Compensation

The response to any AI diagnosis is led by CFIA and guided by their AI Hazard Specific Plan, which describes the principles of controlling the disease, defines the different control zones used for containment, and describes actions that can be taken in the vicinity of the Infected Place.

Upon confirmation of AI (H5 or H7), CFIA can implement several disease containment zones.

The above diagram represents a scenario with one infected farm. If additional farms are declared Infected Places, the sizes of the infected and restricted zones would change accordingly.

Infected Place: A premises where a CFIA presumes or confirms that AI exists.

Infected Zone: A minimum 1 km and up to 3 km zone surrounding an Infected Place. When possible, natural barriers and roadways will be used to facilitate the implementation of disease control procedures.

Restricted Zone: A minimum 10 km radius measured from the Infected Place that surrounds the Infected Zone. The boundaries will be defined by physical geographical barriers.

Security Zone: The geographic area between the perimeter of the Restricted Zone to the edge of the Primary Control Zone.

Primary Control Zone: An area established by the Minister to control a disease by regulating the movement of persons, machinery, animals, animal products and animal by-products. This area includes the Infected, Restricted and Security Zones and will be designed with the objective of controlling the spread of the virus and minimizing the impact on the poultry industry.

The above control zones are based on the standards in the Hazard Specific Plan, but CFIA may also implement different zoning depending on geography and disease pressures. For example, in some cases a 10km zone around the infected place may be implemented without the larger security zone.

 

Surveillance and movement on farms in disease containment zones

Depending on proximity to the Infected Place and the official diagnosis, farms within the containment zones may be required to submit birds for surveillance, to submit regular flock health data, and to conduct pre-movement AI testing prior to shipping live birds or moving eggs from a hatching egg flock.

 

Humane depopulation, disposal, and disinfection on infected farms

The CFIA has the mandate to humanely destroy any AI-positive or highly suspicious AI (H5 or H7) flocks and is responsible for carrying out these actions. Flocks will be humanely depopulated on farm, using carbon dioxide, other recognized mixtures of gas, or another approved method.  To conduct a humane depopulation, extensive work will be required to thoroughly seal the barn.

All infected premises are required to be cleaned and disinfected, by the producer, under CFIA supervision according to CFIA protocols.

 

Compensation

All flocks ordered to be depopulated by CFIA will be compensated as per the Health of Animals Act and regulations.

CFIA may compensate producers for:

  • Animals ordered destroyed
  • Other things ordered destroyed, such as contaminated feed or animal products
  • Disposal costs including transportation of animals
  • Cleaning and disinfecting the equipment used for the disposal
  • Vaccination costs for animals ordered to be treated
  • Fair market value of things ordered destroyed

 

Getting back to normal

While all disease response situations are different, the steps for repopulation usually include the following.

In the Control Area:

  • Farms that have tested positive can only re-stock 21 days after cleaning and disinfection is complete provided no other barns within 10 km have tested positive during that 21 days
  • Uninfected farms located within the Infected Zone must wait until 21 days of negative surveillance results and provided AI has not been detected on farms within 3 km prior to re-stocking
  • In all other zones of the Control Area, re-stocking of barns can occur as per usual
  • Barns that have been re-stocked will need to undergo the surveillance and movement protocols specific to their disease control zone

The release of individual Infected Place declarations can occur 21 days after the original declaration if all AI sampling at that farm has produced negative results.

The larger disease control zones will be maintained until at least 21days have elapsed since the cleaning and disinfection of all confirmed infected premises and negative results of surveillance activities.

After the zones have been released, surveillance activities may continue for 3 months in order to demonstrate to international trading partners that the virus has been eradicated. The OIE will only declare Canada an AI free region 90 days after completion of C&D and no further positive AI results.

 

Ongoing AI surveillance

This CFIA webpage details the programs in place to conduct regular AI surveillance that can act as an early warning system for industry. Surveillance programs occur in both wild life and within the commercial sector.

Wild bird surveillance is coordinated by the Canadian Wildlife Health Cooperative, while surveillance of the commercial sector is performed by the Canadian Food Inspection Agency through its Canadian Notifiable Avian Influenza Surveillance System (CanNAISS).

 

Links to other useful resources:

Inventory of AI cases in Canada

CFIA’s AI Hazard Specific Plan

Steps to take if you suspect an infectious disease in your flock

Canadian Wildlife Health Cooperative world news reports and wild bird surveillance data

Weekly avian influenza updates from the World Health Organisation

 

References

  1. Canadian Food Inspection Agency. 2013. Overview of Avian Influenza prevention, preparedness, and response. Available online, https://bit.ly/33iTSNv
  2. Fourment et al., 2017. The impact of migratory flyways on the spread of avian influenza virus in North America. BMC Evolutionary Biology, 17: 118. Available online, https://bmcecolevol.biomedcentral.com/articles/10.1186/s12862-017-0965-4
  3. Health Canada. 2006. Avian influenza and poultry. Available online, https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/avian-influenza-poultry.html
  4. European Food Safety Authority. 2021. Avian influenza. Available online, https://www.efsa.europa.eu/en/topics/topic/avian-influenza
  5. Canadian Food Inspection Agency. 2015. Avian influenza (AI) – what to expect if your animals are infected. Available online, https://bit.ly/3zDQTeZ