Influenza a Viruses in Man and Animals: The Molecular Basis of Evolution, Epidemiology, and Pathogenicity

Abstract

Influenza viruses are classified into three types, A, B and C according to their different biological and biochemical characteristics. Recent studies have indicated that influenza C viruses differ from influenza A and B viruses in their genomic structure, in the type and distribution of the biological activities of their viral glycoproteins, and in the substrate specificity of their receptor destroying enzymes (1, 2). These differences provide the basis to classify influenza C viruses separately from the A and B type viruses. Of the influenza A and B viruses, which differ in the antigenicity of their inner components, the A type viruses appear to be the most important disease agents. They have been found in natural infections in various mammalian species, including man, pig, horse, mink, seal, whale and in a wide variety of different avian species. In mammals, influenza viruses usually cause an acute respiratory disease, whereas in birds, depending on the virus strain and the host, the infection may lead to an inapparent or a systemic fatal disease, known by the term fowl plague.KeywordsInfluenza VirusAvian Influenza VirusSwine InfluenzaReceptor Binding SiteSwine Influenza VirusThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.