Orthomyxoviridae

Orthomyxoviridae is a family of RNA viruses, which includes seven genera: Alphainfluenzavirus , Betainfluenzavirus , Deltainfluenzavirus , Gammainfluenzavirus , Isavirus , Thogotovirus , and Quaranjavirus . Viruses in the first four genera, which are identified by antigenic differences in their nucleoprotein (NP) and matrix (M) proteins, cause influenza disease in vertebrates, including birds, humans, and other mammalian species. Influenza viruses are divided into four types, including influenza A, B, C, and D viruses, based on antigenic differences in their NP and M proteins. Influenza A and B viruses have two major surface glycoprotein antigens: hemagglutinin and neuraminidase. The first description of avian influenza, a contagious disease of poultry associated with high mortality, was reported in northern Italy in 1878 and was termed “fowl plague” initially. Swine influenza is an important respiratory disease of pigs. Influenza is an acute respiratory disease of horses.