Avian influenza, commonly known as bird flu, is a highly contagious viral disease that can infect various species of birds, including domestic poultry as well as wild birds such as waterfowl. Avian influenza viruses are classified into low pathogenic (LPAI) and high pathogenic (HPAI) strains based on their ability to cause disease and mortality in poultry. Most LPAI strains cause little to no signs of illness in birds. However, some LPAI virus strains are capable of mutating into HPAI viruses which can lead to severe disease and death in domestic bird populations. In this article we talk about Avian Influenza in Waterfowl-Prevention and Control.
Waterfowl, including ducks and geese, can carry avian influenza viruses in their intestines and respiratory tract and shed the viruses in their saliva, nasal secretions and feces while showing little or no signs of illness. This makes surveillance and control in wild waterfowl populations challenging. However, since waterfowl can introduce avian influenza to poultry flocks, it is critical to understand the role of wild birds in outbreaks and transmission so proper prevention and control strategies can be implemented.
Prevention of Avian Influenza in Waterfowl
Preventing contact between domestic birds and infected wild bird populations is the most effective biosecurity strategy to reduce transmission. Steps that can help prevent the introduction of avian influenza from waterfowl include:
- Preventing direct contact between wild migratory waterfowl and domestic poultry through physical separation. Install bird-proof netting or overhead barriers around outdoor access areas. Place poultry houses a recommended minimum distance from lakes, ponds and wetlands.
- Eliminating sources of food or water that could attract wild waterfowl near poultry facilities. Clean up any feed spills and avoid landscaping water features or habitats that appeal to wild ducks and geese.
- Using disinfectant foot baths at the entrance and exit areas of poultry houses. Require all caretakers to wear protective clothing and footwear designated only for the facility. Isolate any new introductions or returning show birds before allowing contact.
- Avoiding the use of surface water sources like lakes or ponds for drinking water in poultry houses. Chlorinate water supplies if needed to inactivate any viral contaminants from wild bird feces.
- Practicing strict biosecurity on poultry farms, live bird markets and at slaughterhouses, processing facilities and live bird transportation trucks or crates. All equipment, workers and visitors should be properly disinfected and cleaned.
Routine surveillance and reporting of unusual bird sickness or deaths among commercial and backyard poultry flocks is also critical. Any highly pathogenic infections can then be quickly identified and contained.
Control Measures for Avian Influenza in Waterfowl
If despite preventive efforts, HPAI is detected in wild waterfowl or transmission to domestic flocks occurs, swift action is required to control spread.
USDA emergency response plans can include:
- Immediate quarantine and stringent movement controls on infected premises and surrounding high-risk areas.
- Rapid culling (depopulation) of infected and exposed flocks, with proper carcass disposal.
- Increasing active surveillance in the region by state veterinarians to identify any further spread between premises.
- Cleaning and disinfection of affected facilities as well as transport vehicles and equipment.
- Temporary closure of live bird markets, auctions and slaughter plants in the quarantine zone.
- An epidemiological investigation into source of the outbreak and mapping of risky contacts.
If the outbreak escalates into a major epidemic, emergency vaccination protocols may be implemented for high-risk but still uninfected flocks. Antiviral medications are also sometimes administered to treat or prevent clinical signs.
Zoning, compartmentalization and regionalization management strategies may also help restrict trade barriers to unaffected poultry businesses while controlling an avian influenza outbreak.
The challenges posed by recurrent avian influenza infections require cooperative prevention and control efforts between poultry producers, wildlife agencies, diagnostic labs and local state and federal animal health authorities. Continued research on transmission risks, diagnostic testing, new vaccines and best management practices are also needed to enhance future biosecurity and limit the impacts of this costly viral disease.
Implementing sound biosecurity measures provides the best protection against avian influenza for both commercial producers and small backyard poultry flocks. But producers should remain vigilant and report any unusual mass sickness or deaths to state animal health officials immediately since rapid detection and containment is necessary to control outbreaks, especially those involving a highly pathogenic strain. Understanding the role wild waterfowl play in avian influenza spread and evolution allows poultry owners to target risky interfaces and mitigate contact. With prompt action and coordinated efforts between stakeholders, the risks this virus poses to domestic flocks as well as human health can be reduced. I sincerely hope you find this “Avian Influenza in Waterfowl-Prevention and Control” article helpful.