Genetic Analysis of Highly Pathogenic Avian Influenza H5N1 in West Delta Governorate

Avian influenza viruses became widely distributed in most Middle Eastern countries, causing high mortality rate and severe economic losses in poultry industry especially when complicated with other pathogens. The continuous evolution of highly pathogenic H5N1 avian influenza viruses (HPAI- H5N1) has resulted in multiple diverse groups based on their haemagglutinin (HA) sequences. In this study, samples from 40 broiler chicken farms during 2014 - 2017 were screened for HPAI- H5N1 Results showed that 15 flocks (37.5%) were positive for HPAI-H5 all of them non vaccinated . Furthermore, full sequencing of HA and NA gene for 3 isolates isolated during 2017 showed that the viruses were clustered with Egyptian viruses from clade 2.2.1.2 and closely related to viruses from neighboring countries.