Influenza Sampler Presenting sample chapters on influenza from the Manual of Clinical Microbiology, 12th Edition, Chapter 86 “Influenza Viruses” by Robert L. Atmar This chapter discusses seasonal influenza strains as well as novel swine and avian influenza strains that can infect people and have pandemic potential. Chapter 83 “Algorithms for Detection and Identification of Viruses” by Marie Louise Landry, Angela M. Caliendo, Christine C. Ginocchio, Randall Hayden, and Yi-Wei Tang This chapter outlines technological advances for the diagnosis of viral infections. Chapter 113 “Antiviral Agents” by Carlos A.Q. Santos and Nell S. Lurian This chapter reviews antiviral agents approved by FDA and their mechanism(s) of action. Photo Credit: CDC/ Douglas Jordan, Dan Higgins Influenza Viruses* ROBERT L. ATMAR Send proofs to: Robert L. Atmar Email:
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[email protected] [email protected] [email protected] 86 TAXONOMY The segmented genome of influenza viruses allows the The influenza viruses are members of the family Orthomyxo- exchange of one or more gene segments between two viruses viridae. Antigenic differences in two major structural pro- when both infect a single cell. This exchange is called teins, the matrix protein (M) and the nucleoprotein (NP), genetic reassortment and results in the generation of new and phylogenetic analyses of the virus genome are used to strains containing a mix of genes from both parental viruses. separate the influenza viruses into four genera within the Genetic reassortment between human and avian influenza family: Influenzavirus A, Influenzavirus B, Influenzavirus C, virus strains led to the generation of the 1957 H2N2 and and Influenzavirus D.