Pneumovirus

Pneu·mo·vi·rus

(nū'mō-vī'rŭs), A genus of viruses (family Paramyxoviridae) including respiratory syncytial virus, which causes severe lower respiratory tract disease in infants. Nucleocapsids are 13-15 nm in diameter and thus intermediate in size between other Paramyxoviridae and the Orthomyxoviridae; cytoplasmic inclusions are considerably more dense than those of other viruses in the family.