Etiology:  PVM is an enveloped RNA paramyxovirus of the pneumovirus group.

Incidence:  The incidence of disease in research colonies is rare for PVM.

Transmission: The primary route of infection is by direct contact with infected animals during the first two weeks of infection when the virus is shed.  The disease is usually enzootic in a colony in which susceptible animals are regularly introduced.  Interspecies transmission (to and from gerbils, mice, hamsters) is possible.

Clinical Signs:  PVM infections usually produce no clinical disease.

Pathology:  Histologic lesions may include very mild perivascular and focal interstitial lymphocytic infiltrates.

Diagnosis:  Most respiratory virus infections are identified by screening sera by MFI or IFA.