Introduction Paramyxoviridae include parainfluenza mumps rubeola (measles) respiratory syncytial virus (RSV) All are associated with lungs all contain surface F (fusion) protein causes respiratory epithelial cells to fuse resulting in multinucleated giant cells not found in orthomyxoviridae children most infections occur in kids viremia viruses are disseminated throughout the body Characteristics in common RNA single-stranded not segmented as in orthomyxoviridae negative-sense linear enveloped helical nucleocapsid contain hemagglutinin (HA) and neuraminidase (NA) except RSV rubeola (measles) has no NA HA and NA are found in the same glycoprotein spike, unlike in orthomyxoviridae