Experimental labyrinthitis in rats caused by infecting with virus causing hemorrhagic fever with renal syndrome (HFRS).

Acute and persistent viral infection of the inner ear of rats was induced with hemorrhagic fever with renal syndrome (HFRS) virus following intraperitoneal inoculation. Newborn (within 24 h after birth) rats were inoculated intraperitoneally (i.p.) with HFRS virus (B-1 strain), and the cochlea was examined using an immunohistochemical technique for the localization of viral antigens 1 week (acute infection) and 1 year (persistent infection) after infection. Virus-specific antigens were detected in the inner ear structures of the rats suffering from both acute and persistent infection. Morphological changes in the inner ear structures of these rats were observed, with hemorrhage and infiltration of lymphocytes and macrophages. Moreover virus could be isolated from the blood of all infected rats. In the present study, we have proved that HFRS virus can infect the inner ear via the viremia.