Experimental infection of Akodon molinae (Rodentia, Cricetidae) with Junín virus.

Experimental infection with the XJ-Clone 3 strain of Junín virus in laboratory bred Akodon molinae, a cricetid rodent inhabiting the borders of endemic Argentine hemorrhagic fever areas, was studied. Suckling animals inoculated intracerebrally proved sensitive and became chronically infected. Sixty percent of the rodents showed neurologic involvement, with mortality reaching 60%. Virus was recovered from the brain at 7, 15, 21, 37, and 57 days postinfection (pi). By immunofluorescence (IF), viral antigens were observed up to 182 days pi in cells of the central nervous system (CNS). Concurrently, immunoglobulin deposits were detected in infected CNS cells from 21 up to 182 days pi. These deposits increased with the progression of the immune response as measured by IF antibodies. The detection of immune complexes in brain cells of apparently healthy animals suggests that neither viral replication nor the development of a humoral immune response are necessary requisites for neurovirulence in this host. Infection of adult rodents by different routes failed to induce disease or mortality and virus could not be recovered from oral swabs, blood, or organs. Our data suggest that Akodon molinae could play a role in nature as an alternative reservoir of Junín virus in addition to the main reservoir, Calomys musculinus.