Avian influenza, or bird flu, is a zoonotic disease caused by influenza A viruses of the Orthomyxoviridae family, classified by two surface proteins: haemagglutinin (H1–H16) and neuraminidase (N1–N9). These viruses vary in severity; low-pathogenic strains cause mild respiratory issues or reduced egg production, while highly pathogenic strains (HPAI) can lead to severe, often fatal, systemic disease. As per the recent FAO report, there have been 297 reported HPAI outbreaks in animals across five regions, mainly due to H5N1 (254 cases), followed by H5Nx (33), H5N5 (9), and H5N9 (1).
Understanding Transmission
Wild aquatic and migratory birds serve as asymptomatic reservoirs of the Avian Influenza virus. These birds transmit the virus to domestic poultry via contaminated environments, where viral shedding occurs through feces, saliva, and respiratory secretions. They can be further spread through direct contact with secretions from infected poultry, contaminated feed, water, and farm equipment. This results in severe economic and production losses for the farmer. The avian influenza virus has a high survival rate even in low temperatures and harsh environments.
Know the signs of Avian Influenza in your flock
Diagnosis methods to determine Avian influenza
Avian Influenza cannot be diagnosed on the basis of clinical signs alone; laboratory testing is also important.
- Molecular techniques like reverse-transcription PCR (RT-PCR), which detect the viral RNA.
- Serological tests such as AGID or ELISA, used to identify antibodies against the virus.
- Genetic sequencing which helps confirm the virus strain and its pathogenicity.
These tests help distinguish Avian Influenza from other poultry diseases such as Newcastle disease, infectious bronchitis, or mycoplasmosis.
Controlling the Spread
Avian Influenza control strategies are designed to prevent, manage, or completely eradicate the infection from the farm. The following key measures may play a vital role in effective disease control of Avian influenza-
Biosecurity (Exclusion and Inclusion):
Implementing strict measures to prevent contact between infected or wild birds and healthy poultry via proper fencing, limiting access to poultry farms, and ensuring hygiene practices for visitors and farm surfaces, equipment, and facilities to eliminate potential virus contamination.
Diagnostics and Surveillance:
Regular monitoring of poultry flocks for signs of illness, including testing for the avian influenza virus through sampling and laboratory analysis.
Elimination of AVIAN INFLUENZA Virus-Infected Poultry:
Humanely eliminating infected poultry and safely disposing of carcasses and contaminated materials to prevent further spread of the virus and environmental contamination.
Decreasing Host Susceptibility to the Virus (Vaccines and Host Genetics):
Developing and administering safe and effective vaccines and improving host resistance to the virus through selective breeding programs to protect poultry flocks from infection.
Education of all Personnel on Infectious Diseases and their Control:
Providing comprehensive training to poultry farmers, veterinarians, and other stakeholders involved in poultry production on proper biosecurity practices, disease recognition, and reporting procedures.