Avian influenza virus and newcastle virus surveillance and characterization in broiler and layer chicken flocks in Egypt

Abstract EN

Considering that highly pathogenic avian influenza H5N1 endemically circulates in the Egyptian poultry population, Active surveillance was undertaken in 195 broiler and layers farms from Eighteen Egyptian governorates resulted in, 34,7 and 24 positive farms for AI H9N2, AI H5N1 and Virulent ND respectively, using RT-PCR.

The genetic analysis of avian influenza viruses of HA gene of the H5N1 type revealed that these viruses are highly pathogenic strains as they are tracking clade 2.2.1 of classic viruses which became endemic in Egypt since 2006.

However, H9N2 viruses revealed that they are low pathogenic as they are tracking G1-lineage of Asian viruses which transmitted to Middle East scince 2000.

Also sequence analysis for F gene for twelve NDV isolates revealed that they are of virulent type and genetically related to genotype VII NDV except two isolates are avirulent type and resemble Lasota- like- strains.

Pathogenecity studies for NDV isolates using ICPI was evaluated for the strain (NDV-EG-567f-2012) which of virulent with ICPI value 1.96.

The analysis of isolated strains by different diagnostic and analytical techniques implies that the H5N1 and H9N2 silent infection exist in Egypt.