Comparative infectivity and transmissibility studies of wild-bird and chicken-origin highly pathogenic avian influenza viruses H5N8 in chickens

Despite the recent advances in avian influenza viruses surveillance and genomic data, fundamental questions concerning ecology evolution of these remain elusive. In Egypt, H5N8 highly pathogenic (HPAIVs) are co-circulating simultaneously with HPAIVs subtypes H5N1 low-pathogenic (LPAIVs) subtype H9N2 both commercial backyard poultry. order to isolate AIVs from wild birds assess their potential causing infection poultry, a total thirty-four cloacal swab samples were collected apparently healthy migratory (Anas acuta, Anas crecca, Rallus aquaticus, Bubulcus ibis) four Egyptian Governorates (Giza, Menoufia, Gharbia, Dakahlia). Based on matrix (M) gene-targeting real-time reverse transcriptase PCR subsequent genetic characterization, our results revealed two positive isolates (2/34) for whereas no detected. Genetic characterization full-length haemagglutinin (HA) genes clustering reported within genotype 5 clade 2.3.4.4b. The bird-origin virus isolated cattle egret its transmission capability between chickens was investigated compare chicken origin AIV. Chickens inoculated showed varying clinical signs detection shedding. contrast, contact less levels secretion indicating efficient inter/intra-species transmission. These demonstrated possibility spreading bird chicken. conclusion, study highlights need continuous frequent monitoring diversity as well poultry sectors better understanding determining nature viruses, which is predict any future threat through reassortment threaten human animal health. Likewise, an assessment coverage efficacy different vaccines or vaccination regimes field conditions should be reconsidered along strict biosecurity measures.