The present invention relates to a novel isolated avian hepatitis E virus
having a nucleotide sequence set forth in SEQ ID NO:1 or its
complementary strand. The invention further concerns immunogenic
compositions comprising this new virus or recombinant products such as
the nucleic acid and vaccines that protect an avian or mammalian species
from viral infection or hepatitis-splenomegaly syndrome caused by the
hepatitis E virus. Also included in the scope of the invention is a
method for propagating, inactivating or attenuating a hepatitis E virus
comprising inoculating an embryonated chicken egg with a live, pathogenic
hepatitis E virus and recovering the virus or serially passing the
pathogenic virus through additional embryonated chicken eggs until the
virus is rendered inactivated or attenuated. Further, this invention
concerns diagnostic reagents for detecting an avian hepatitis E viral
infection or diagnosing hepatitis-splenomegaly syndrome in an avian or
mammalian species comprising an antibody raised or produced against the
immunogenic compositions and antigens such as ORF2 proteins expressed in
a baculovirus vector, E. coli, etc. The invention additionally
encompasses methods for detecting avian HEV nucleic acid sequences using
nucleic acid hybridization probes or oligonucleotide primers for
polymerase chain reaction (PCR).