Properties of Paramyxovirus Isolated from Budgerigars with an Acute Fatal Disease

Abstract

In the early period of 1975, an acute fatal disease was prevalent among caged budgerigars throughout Japan. Clinical, pathologic and virologic studies were carried out on affected birds collected in Tokyo and Saitama Prefectures. The disease was characterized by inappetence, diarrhea, ruffling feathers, droopiness and a high fatality of 90-100%. No gross lesions were observed in birds that died of the illness. His. tologic examination revealed multiple focal necroses along with the formation of multinucleated giant cells in the liver and spleen. A viral agent was isolated by inoculation of chicken kidney cell cultures with the pooled extract of liver and spleen collect from affected birds, and designated as strain TI. By inoculating the isolated virus into healthy budgerigars, clinical symptoms and pathologic lesions similar to those in field cases were induced and the virus was recovered from the liver in the inoculated birds.
On the basis of its physicochemical properties, the isolate was identified as a member of the paramyxovirus group. The virus was neutralized with antiserum against the Kunitachi strain of paramyxovirus that had been isolated from a budgerigar by Nakayama et al., but not with antisera against other avian paramyxoviruses, including Newcastle disease, Yucaipa, and Bangor viruses.