Experimental Argentine hemorrhagic fever in rhesus macaques: virus-specific variations in pathology

Two isolates of Junin virus (Espindola and Ledesma) inoculated into rhesus macaques produced distinct lesions which were strain-constant and similar to reported human cases of Argentine hemorrhagic fever. The Espindola isolate was associated with hemorrhagia, necrosis of bone marrow, and mild hepatocellular necrosis. Ledesma isolate was associated with pronounced polioencephalomyelitis and autonomic ganglioneuritis, but very mild or absent hepatocellular necrosis, bone marrow necrosis, and hemorrhagia. Deaths of Espindola-infected macaques were usually attributed to hemorrhagia with severe secondary bacterial infections, while in Ledesma-infected macaques, death was associated either with early severe secondary bacterial infections or slowly progressive polioencephalomyelitis. These two Junin virus isolates demonstrated hemorrhagic viscerotropism or neurotropism in macaques, suggesting that the variety of Argentine hemorrhagic fever syndromes in man may be virus-isolate determined.