Isolation of a paramyxovirus from pigs in Israel and its antigenic relationships with avian paramyxoviruses.

During surveillance of the swine population in Israel a haemagglutinating agent was isolated and identified as a paramyxovirus (PMV). Serological studies based on haemagglutination and neuraminidase inhibition (HI and NI) tests displayed a close antigenic relationship between the isolate and the prototype strain of a variety of the avian PMV serotype 3 (PMV-3). However, comprehensive HI and NI cross-reaction tests between the isolate and PMV-3 reference strains, on the one hand, and the other eight avian PMV serotypes, on the other hand, showed that the viruses compared differed in terms of their antigenic interrelationships with the other avian PMVs and also in the quantitative values of the cross-reactivity. This is interpreted to mean that the swine isolate and the avain PMV-3 prototype strain are different viruses, although very closely related, but are not different isolations of the same virus from avian and mammalian hosts.