Infections with viruses of the genus RESPIROVIRUS, family PARAMYXOVIRIDAE. Host cell infection occurs by adsorption, via HEMAGGLUTININ, to the cell surface.
A genus of the family PARAMYXOVIRIDAE (subfamily PARAMYXOVIRINAE) where all the virions have both HEMAGGLUTININ and NEURAMINIDASE activities and encode a non-structural C protein. SENDAI VIRUS is the type species.