Publication Type: | Journal Article |
Year of Publication: | 2003 |
Authors: | Hinshaw, VS |
Journal: | Avian Diseases |
Volume: | 47 |
Date Published: | 2003 |
ISBN Number: | 00052086 |
Keywords: | Europe, Meleagris, Meleagris gallopavo, Phasianidae |
Abstract: | Influenza A viruses infect and cause disease in humans, lower mammals and birds. The largest reservoir of these viruses exist in migratory waterfowl, particularly ducks. Viruses in these birds include all known antigenic subtypes, do not cause obvious disease in the ducks themselves and are excreted in high titers in feces, thereby facilitating transmission in the natural setting. The viruses in these birds have been proposed as a source of viral genes for viruses appearing in humans and have been implicated as a source of viruses responsible for disease outbreaks in mammals as seals, whales, mink, pigs and domestic birds, as chickens and turkeys. Antigenic, genetic and biologic characterization of viruses from these different hosts indicate that the viruses are of avian origin and that a likely source is the migratory waterfowl. Other sources may also be involved, for example, an outbreak in turkeys in the U.S. involving H1N1 viruses involved viruses most closely related to those circulating in pigs whereas, in Europe, N1N1 viruses appearing in pigs were more closely related to avian strains. Thus, it is apparent that interspecies transmission of influenza A viruses in nature does occur and that migratory waterfowl are critically involved in this important event. Studies on the genetic basis of interspecies transmission have really just begun; studies on the sequence in the receptor binding sites of the hemagglutinins of avian versus mammalian viruses suggest that the viral hemagglutinin plays an important role in the ability (or inability) of the virus to replicate in the intestinal tract of birds, thereby altering the tissue tropism, and potentially the host range, of the virus. Studies on the molecular basis of interspecies transmission are required to understand why this event does occur and, in actually, why it occurs so infrequently in view of the reservoir of viruses circulating in the waterfowl. |
URL: | http://www.jstor.org/stable/3298738 |
Short Title: | Avian Diseases |
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