PATHOGENESIS OF SENDAI VIRUS-INFECTION IN THE SYRIAN-HAMSTER

Young adult male Syrian hamsters were inoculated intranasally with Sen dai virus, then killed and examined at postinoculation days (PID) 3, 5 , 7, 9, 12, 16, and 21. Evaluation included clinical assessment, histo logic examination, immunohistochemistry, viral isolation, and antibody response. Inoculated and control hamsters remained asymptomatic throu ghout the study, There was a focal to segmental rhinitis involving res piratory tract epithelium lining the dorsal and veneral. meatus and na sal septum, and segmental lesions involving all regions of the trachea , At PID 5 and 7, there was focal bronchitis and bronchioloalveolitis, respectively, In general, most lesions had resolved by PID 12, althou gh in hamsters examined at PID 21, residual lesions were present in th e nasal passages in one of three, and in the trachea in two of three a nimals, In immunoperoxidase-stained preparations, viral antigen was pr esent in the respiratory tract epithelium of the nasal passages and tr achea beginning at PID 3, with extension to scattered bronchi at PID 5 . Sendai virus was recovered from the lungs of inoculated animals at P ID 5, Antibodies to Sendai virus were first detected at PID 7, and tit ers remained high throughout the remainder of the 21-day study, This r eport provides additional evidence that Syrian hamsters are susceptibl e to Sendai virus infection, and that the lesions and sites of replica tion in the upper and lower portions of the respiratory tract are simi lar to those observed in susceptible strains of laboratory mice.