Submitted to: Veterinary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/2/2007
Publication Date: 4/23/2008
Citation: Pillai, S.S., Suarez, D.L., Pantin Jackwood, M.J., Lee, C. 2008. Pathogenicity and transmission studies of H5N2 parrot avian influenza virus of Mexican lineage in different poultry species. Veterinary Microbiology. 129:48-57.
Interpretive Summary: Avian influenza virus is naturally found in wild birds, primarily ducks, gulls, and shorebirds. Occasionally the virus can be transmitted to poultry including chicken and turkeys where the virus can be characterized as being of low virulence or as being of high virulence. Recently, a H5 avian influenza virus was isolated from a sick Amazon parrot from California. It was unusual to find the virus in parrots and additional studies were done to characterize the virus. The virus based on its genetic code was similar to viruses seen in chickens in Mexico and Central America. The virus could infect, but did not cause disease, in chickens, ducks, and turkeys. The virus seemed to grow best from turkeys which is further evidence that is was related to Mexican lineage viruses. The study provides additional reasons to control of movement of parrots and other psittacines across U.S. borders to prevent the introduction of dangerous viruses.
Technical Abstract: In 2004, a low pathogenic H5N2 influenza virus was identified in a psittacine bird for the first time in the United States. Sequence and phylogenetic analysis of the hemagglutinin gene grouped the parrot isolate under the Mexican lineage H5N2 viruses (Subgroup B) with highest similarity to recent chicken-origin isolates from Guatemala. Antigenic analysis further confirmed the close relatedness of the parrot isolate to Mexican lineage viruses, the highest cross reactivity being demonstrated to Guatemala isolates. In vivo studies of the parrot isolate in chickens, ducks, and turkeys showed that the virus could replicate to high titers in these birds and efficiently transmit to contact control cage mates. The possibility that the parrot harboring the virus was introduced into the United States as a result of illegal trade across the border, provides additional concern for the movement of foreign animal diseases from neighboring countries. Considering the potential threat of the virus to domestic poultry, efforts should be continued to prevent the entry and spread of influenza viruses by imposing effective surveillance and monitoring measures.