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.

 

If you would like more information about what to do if you suspect AI on your farm and how it will be handled, please refer to this page: A guide to events and protocols when Avian Influenza is detected

 

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.

 

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