دراسات وأبحاث  Studies & Research

1من اصل1 

Avian Influenza H9N2 infection, the hidden fun

Dr Ahmed Elbestway

Lecturer of poultry diseases

Fac. Vet. Med.

Damanhour Univ.

Avian influenza (Al) is caused by type A avian influenza virus, a member of Orthomyxoviridae (8 segmented RNA).

H8N2 subtype viruses generally exist as low pathogenicity influenza viruses causing mild to moderate disease (mainly respiratory enteric symptoms). However, they have been associated with severe morbidity and mortality in poultry as a result of co-infection with other pathogens.

The first H9N2 influenza virus was isolated from turkeys in Wisconsin in 1966.

Avian influenza H9N2 subtype had been reported in Egypt since 2012. it can birds, pig and human being.

The disease is mainly air born transmitted and the poor biosecurity system especially live bird markets resemble a high risk in this disease transmission.

As we mentioned before this virus is mainly low pathogenic but severe morbidity and higher mortality rates (may reach 20-30%) in the infected poultry flocks results from co-infection with other pathogens or live Vaccines (as ND &/ or IBV vaccines) and predisposing non-infectious factors as poor management, poor ventilation, bad litter condition and increased dust and ammonia levels. In addition to immunosuppressed birds.

Genetically the haemagglutinin glycoprotein for influenza viruses is produced as a precursor, HA0, which requires post translational cleavage by host proteases before it is functional and virus particles are infections.