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Pronunciation: par'a-mik'so-vir'i-de

Definition: A family of RNA-containing viruses about twice the size of the influenza viruses (Orthomyxoviridae) but similar to them in morphology. Virions are 150–300 nm in diameter, enveloped, ether sensitive, and contain RNA-dependent RNA polymerase. Nucleocapsids are helical, considerably larger than those of the influenza viruses, and contain single-stranded unsegmented RNA. Four genera are recognized: Paramyxovirus, Morbillivirus, Rubulavirus, and Pneumovirus, all of which cause cell fusion and produce cytoplasmic eosinophilic inclusions. Diseases associated with these viruses include croup and other upper respiratory infections, measles, mumps, and pneumonia.

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© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review date: Sep 19, 2016.