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United States Department of Agriculture, Animal and Plant Health Inspection Service, Riverdale, Maryland 20737, USA
Address for correspondence: Cheryl Hall, D.V.M., M.A.M., A.C.P.V., United States Department of Agriculture, Animal and Plant Health Inspection Service, National Center for Import and Export, 4700 River Road, Unit 46, Riverdale, MD 20737. Voice: 301-734-8715; fax: 301-734-4982. cheryl.i.hall{at}aphis.usda.gov
Avian influenza (AI) viruses are Type A influenza viruses of the Orthomyxoviridae family. There are 15 subtypes of the virus widespread in migratory waterfowl throughout the world. It has become increasingly evident that some low pathogenic avian influenza (LPAI) H5 or H7 viruses have the capacity to mutate into the more virulent strains that cause extensive economic losses and high mortality. Recent AI disease outbreaks in several countries have increased attention and concern over low pathogenic H5 and H7 AI viruses. This heightened international concern increases the risk of unnecessary trade bans. For the US poultry industry, avian influenza continues to be a challenge to the flow of trade. On one hand, there is the increased focus of world attention on the H5 and H7 low pathogenic AI virus and the possibility of mutation. On the other hand, there are the factors contributing to our finding of infected flocks. Among these, perhaps the most important is the ever-present reservoir of virus in the migratory waterfowl population. With the discovery of exposed flocks comes the threat of trade bans.
Key Words: avian influenza • Type A influenza viruses • poultry disease • trade bans • mutation This article has been cited by other articles:
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