Virus-specific factors in experimental Argentine hemorrhagic fever in rhesus macaques.

A nonhuman primate model for Argentine hemorrhagic fever has been developed that closely mimics the human clinical syndrome. Parenteral infection of adult Macaca mulatta with low-passage isolates of two Junin viral strains resulted in distinctive hemorrhagic or neurological disease in rhesus macaques that correlated with clinical illness patterns present in the humans from whom the viral strains were obtained. Transient leukopenia, together with thrombocytopenia and secondary bacterial septicemia, were documented among animals infected with both viral strains. In contrast, differing patterns of viremia, oropharyngeal viral shedding, and antibody response occurred in the two virus-infected groups. These results, together with postmortem virologic and histopathologic findings, suggest that viral-strain-specific factors are important determinants of clinical disease patterns in this model system.