Submitted to: United States Animal Health Association Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 2000
Publication Date: November 1, 2000
Technical Abstract: A "small round virus" was isolated from the thymus of PEMS-infected poults and determined to be a new strain of astrovirus. This astrovirus reproduced PEMS clinical disease in turkey poults. An RT-PCR diagnostic test was developed and showed that the astrovirus was present in commercial turkey flocks. The astrovirus was not inactivated by many commonly used disinfectants except formaldehyde and Virkon S disinfectant. Turkeys faile to produce a humoral immune response against the astrovirus. A single multiplex RT-PCR test was developed that detected and differentiated astrovirus, reovirus, and coronavirus from commercial turkey flocks. H5N1 avian influenza (AI) viruses from geese in Hong Kong isolated in 1999 shared some genes with the human/chicken viruses of 1997 and were highly pathogenic for chickens, but not for mice. The Hong Kong H5N1 viruses of 1997 can cause disease in a variety of gallinaceous birds, geese and emus, but did not cause disease in ducks and pigeons. Expression of the nonstructural protein was sufficient to cause cell death and required the RNA-binding domain of the protein, but viruses with mutated non-structural genes still induced apoptosis. A rapid test to confirm the presence of avian influenza was developed and a baculovirus expressed hemagglutinin protein was produced for use with hemagglutination inhibition assays.