English : Pathogenicity of two Egyptian H5N1 highly pathogenic avian influenza viruses in domestic ducks
Abstract Domestic ducks have been implicated in the
dissemination and evolution of H5N1 highly pathogenic
avian influenza (HPAI) viruses. In this study, two H5N1
HPAI viruses belonging to clade 2.2.1 isolated in Egypt in
2007 and 2008 were analyzed for their pathogenicity in
domestic Pekin ducks. Both viruses produced clinical signs
and mortality, but the 2008 virus was more virulent,
inducing early onset of neurological signs and killing all
ducks with a mean death time (MDT) of 4.1 days. The
2007 virus killed 3/8 ducks with a MDT of 7 days. Full-
genome sequencing and phylogenetic analysis were used to
examine differences in the virus genes that might explain
the differences observed in pathogenicity. The genomes
differed in 49 amino acids, with most of the differences found in the hemagglutinin protein. This increase in path-
ogenicity in ducks observed with certain H5N1 HPAI
viruses has implications for the control of the disease, since
vaccinated ducks infected with highly virulent strains shed
viruses for longer periods of time, perpetuating the virus in
the environment and increasing the possibility of trans-
mission to susceptible birds.
Publication year 2016
Pages 1-15
Organization Name
serial title ARCH. VIROL.
Author(s) from ARC
Publication Type Journal