The Avian Influenza Virus

Avian Influenza is caused by an Influenza A virus.

The virus is further classified into subtypes based on:

1. The glycoproteins haemagglutinin (H) and neuraminidase (N) present on the virus.
   • 15 H subtypes (H1-H15)
   • 9 N subtypes (N1-N9)
     
     
2. The ability of the virus to cause disease
   • Highly Pathogenic Avian Influenza (HPAI) - Can cause up to100% mortality.
   • Low Pathogenic Avian Influenza (LPAI) – Causes a mild disease with lower mortality

LPAI subtypes, especially H5 and H7, have the ability to mutate to HPAI after circulation in a poultry population.

Read more about Highly Pathogenic Avian Influenza